Back in February Labour announced that it would, if it took power, begin an “immediate and independent review into the culture and practices of HMRC with regard to tax avoidance.”

This politicisation of the question whether HMRC retained public confidence diffused the logic of the demand. But the force of the argument sufficed to overcome this handicap. A broad church of respected industry figures coalesced around a single answer. Paul Aplin, Chair of the ICAEW Tax Faculty Technical Committee, Professor Judith Freedman at Oxford University, Ray McCann and Richard Murphy all joined in the call for a review.

The politics have come and gone. But the issue has not gone away. Paul Aplin has repeated the call. Twice [£]. As has Bill Dodwell, Head of Tax Policy at Deloitte. And so, too, apparently, Grant Thornton. Let me, here, add my voice to theirs.

There is much that we agree on. We each of us identify the need for a review as stemming from a breakdown in public confidence in HMRC: of this, and the threat it poses to social cohesion, there can be no serious doubt.

We all, no doubt, understand the difficulties arising from a constrained funding environment. But even proceeding from this premise, there remains much that might be done to improve the relationship between HMRC and the public it serves.

Political accountability must be enhanced: whilst I have heard the arguments, I still do not understand the case for HMRC remaining a department without a minister.

Transparency goes arm in arm with accountability: the culture of HMRC must change so that it proceeds instead from the assumption that the public has a legitimate interest in understanding the basis on which decisions are made. Whilst plainly there will be hard cases, even under the law as it presently stands there is high level authority for the proposition that HMRC could move some way from the status quo.

Whilst there is disagreement amongst professionals as to whether the recent extensions to HMRC’s powers are justified, there is an emergent consensus that those powers are subject to inadequate internal and external control and supervision. These failings are not only to be found at HMRC – but it is there that rebalancing the culture must begin.

As I and many others have observed, the proper functioning of our tax system is materially contingent upon the public’s voluntary obeisance to it. That obeisance is under strain. Lose it and it won’t be recovered in a dozen Finance Bills.

Those outside the world of tax might not appreciate quite what an influence Margaret Hodge has had on it.

Through her leadership qualities and quiet, behind-the-scenes, consensus building she led a cross-party committee to the heart of one of the most politicised issues of the last Parliamentary term: tax avoidance. To do this whilst maintaining its unity is a remarkable achievement.

Under her leadership, that Committee drove questions of tax and tax avoidance to the top of the political agenda. That achievement kept the political pressure on the Coalition Government to deliver on tax avoidance. And, politically inconvenient to the left though it is, the truth is that, on tax avoidance at least, the Coalition Government responded. It is impossible to know the extent to which responsibility for those legislative changes can be attributed to the work of the Public Accounts Committee. But on any view considerable credit is due to it and to her.

Tax avoidance can’t merely be tackled through changes in the law. It requires public engagement too. Through her acute analysis of the pressure points of, particularly consumer facing, businesses she achieved a number of voluntary changes in corporate behaviour. The effects of this positive drift will continue to be seen.

And we should not forget the important role she played in achieving those (regrettably, still modest) enhancements in HMRC’s public accountability that were delivered during the course of the last Parliament.

And she did all of this whilst finding the time to support and develop the effectiveness of Labour Party activists.

The tax profession, by and large, will be delighted to see the back of her. It’s right to acknowledge that one can’t walk a highwire for five years without occasionally falling off. But, nevertheless, I struggle to see any other serious claimant to the title of most influential Opposition MP of the last Parliamentary term. Who else, after all, can lay claim to have inspired two words: a Hodging and a MarGarotting?

This tax year the highest earning 5,000 people in the United Kingdom will pay around £9bn of income tax. That amounts to around 5% of the total income tax paid. And it is Labour’s intention, should it be in Government, that this burden on the wealthiest shall increase.

The Party’s manifesto includes measures to raise the so-called additional rate of tax from 45% to 50%; to withdraw the remittance basis of taxation from non-doms; and to tax as income rather than capital performance bonuses – described as ‘carried interest’ – earned by certain types of fund manager.  Whether these measures generate additional tax revenue – or just column inches – will depend upon whether it can persuade those 5,000 people, and others like them, to stay. And on whether it can persuade more to join or replace them.

Labour is absolutely right to believe the wealthy will continue to want to live in the United Kingdom. It is – and will remain – politically stable, an attractive place to invest, with an educational system in international demand, and an unrivalled cultural mix. This has long been – and should remain – London’s real offer to the internationally mobile.

We’ve never sought to go head-to-head on tax with Monaco, or Switzerland, or Belize. We don’t need to compete with the Poundstore nations. Labour’s offer is about quality of life – but that doesn’t mean price can be ignored. It can tip to New York those who might otherwise move to London. It could – critically, if handled poorly – precipitate the departure of those who might otherwise stay. To pretend otherwise is hubris.

How should any new Labour Government face up to that challenge? How can it continue to capitalise on the attractiveness of London to increase the ranks of the wealthy who choose to make the United Kingdom their home?

Roll back the clock to 2010. The then new Government faced challenges of its own: the need to encourage investment – foreign and domestic – in a cold fiscal climate. It did this through a Corporate Tax Road Map in which it set out its stall to the business community: “Come here, invest here,” was the pitch, “and we will deliver to you a stable fiscal mix for the life of the Coalition.”

As a piece of advocacy, it delivered in spades. If you ask – as I have had occasion to do – tax professionals, tax directors, the business community what single tax decision was the best the Coalition made, agreement coalesces around the road map. Businesses like low rates of corporation tax – although a recent KPMG survey revealed they rank a distant third to low interest rates and a flexible labour market as key to our recovery – but what they love is certainty. And that’s what the Road Map provided.

The 2010 challenges are not so very different from those an incoming Labour administration would face: the need to make a case for the wealthy to call London home. A Personal Tax Road Map could, it seems to me, do that job.

Such would undoubtedly be a more ambitious exercise than its Corporate tax equivalent. The Coalition eschewed suggestions it should attempt a Road Map for personal taxes. This is in good part because personal taxes make up a much larger part of the overall tax mix: individual income taxes – including National Insurance Contributions – contribute on their own around half of our overall tax take. Prudent Government does not lightly tie its hands to such important fiscal levers.

But then Coalition policy was to cut the tax burden on the wealthiest – the blended income tax rate paid by the highest earning 5,000 has fallen from just over 43% in 2012-13 to just over 39% in 2014-15. And a new Conservative government has promised that rate would fall more should they be returned to power. It’s not to the wealthy the Conservatives need to make their case.

Labour, on the other hand, needs that piece of advocacy. It needs to renew the promise unambiguously made by Ed Balls not to raise the top rate beyond 50%. It needs to reassure global employers that the replacement for the jettisoned non-dom regime will be shot through with considerations of practicality and yield. That it will be a Government that recognises that for the fruits of success to be shared fairly you first have to grow them. The present Shadow Cabinet absolutely understands this – but it still needs to make the case.

It has been said, and rightly, that I act for tax avoiders. But there is some context.

In the area in which specialist tax barristers work, there are only two types of client. There is HMRC, which is always arguing that someone should pay more tax. And there are those on the other side (let’s call them ‘taxpayers’) who are arguing that they should pay less tax. Those are the only clients there are.

Throughout my career – from the very earliest moments – I have sought work from HMRC. I have sought it because I wanted to appear on both sides of the divide, because I thought it would be interesting, and because I thought I had something to offer to HMRC. In 2013, after many rejected applications to join the Attorney General’s Panels, from which HMRC chooses its advocates, I was accepted onto the A Panel, the most prestigious of those panels. To the best of my knowledge, I was then the only pure specialist tax barrister ever to be appointed onto the A Panel. So I have always sought work from HMRC – despite the fact that the rates of pay have been much lower.

The vast majority of my work has been for taxpayers – and a majority of that work involves acting in courts and tribunals for taxpayers who have engaged in what are called (in the trade) “marketed tax avoidance schemes.” That work is exceptionally technically demanding – and the members of the Bar who are experienced in it are few in number. I am subject (as are all barristers) to the ‘cab rank rule’. That rule obliges me to accept such instructions as I am offered. It exists to protect the principle that everyone is entitled to a fair trial. And although the operation of the cab rank rule is (in practice) easy to escape, it’s an important rule and I have never sought to escape it. These factors have dictated the practice that I have today. I make no apology for it: it is where a professional life properly lived has taken me.

However, during my career at the Bar, I have worn two hats. I have worn a barrister’s hat – as set out above – and I have worn a policy hat.

That has at times been an uncomfortable wardrobe.

Wearing my policy hat I have often and publicly called for measures – some of which have subsequently found their way into law, some of which the Coalition has promised to introduce and some of which are in Labour’s Manifesto – which have made life more difficult for my taxpayer clients. I have on a number of occasions met with Directors at HMRC to advise on how HMRC should tackle tax avoidance. I have (in a formal setting) given advice to teams of Inspectors – and Managers – in HMRC’s Counter Avoidance Unit. I have written publicly about abuses by (a small group of) my colleagues at the tax bar. I have proposed measures to the relevant Conservative Party Treasury Minister – and at least one of those measures has become law. I have done all of this without financial reward, without the desire for personal advancement, and I have done it because I have wanted to see our tax system function better.

My clients are entitled to expect that I observe my professional obligations to them – and that I fearlessly advance their interests in court. I have always sought to do that – and the strength of my taxpayer practice is testimony to my success. My clients have not always appreciated the fact that, wearing my policy hat, I have argued, on occasion, against what I might anticipate to be their interests. I have no doubt that this will have cost me new clients. But that has not weighed in my calculations.

In June 2013 I took the decision to start writing this blog. My very first post was entitled ‘How do we solve a problem like avoidance?’ Colleagues have described it (repeatedly) as the longest suicide note in history of a successful practice, but I continue to write and argue for better understanding of the complex field in which I work. But for the fact I represent in court clients who engage in tax avoidance, I would not be able effectively to do this policy work. This is not why I represent taxpayer clients engaging in avoidance, but it is nevertheless true.

I have always been transparent about the type of work that I do. None of this has – as two newspapers, one on the right and one on the left of the political spectrum have put the matter – “emerged”. You have been able to read it in the “About” page of this blog from the first day I started writing it, and indeed on my personal profile page at Devereux Chambers. It has “emerged” in the same way as it has “emerged” that I am a barrister: it has always been there.

So, yes, I act for tax avoiders. But there is some context.

I believe I can document all of the claims set out above.