The motion – "Clear and unambiguous tax law is an invitation to raid the public purse" – will be proposed by a leading QC, Kevin Prosser of Pump Court Tax Chambers, while Paul Lasok QC of Monckton Chambers will oppose. Already, 250 tax experts have applied to attend.
Mr Field [head of tax at Farrer & Co] said: "I don't think there has ever been a tax event like it. Everybody wants to come. Most people accept that we need change if taxing companies is to be made fairer. There is clearly a problem with corporate tax avoidance and one which we have seen has taken on a moral dilemma with lobbying groups like UK Uuncut taking a stand.
"That's why we are asking whether the moment has come to look at whether the hallowed principle of legal certainty – the basis of all tax law – should give way to a more fuzzy concept of fairness."
Legal certainty is a constitutional principle underlying all law-making, but it has become open to challenge when it comes to tax, he said. Working out how much money is lost by tax avoidance is impossible, although many billions more could be raised if Revenue & Customs were to change its approach.
"The boundary between acceptable tax mitigation and unacceptable tax avoidance should be defined in a much vaguer way, so that professional advisers are unable to advise on a strict interpretation. The best advice would be for the advisers to say 'Stay away'. But, if they give boundaries, then the avoidance industry will find ways around it."
Perhaps I'm wrong. Perhaps it would reduce it down to one line: "the tax you owe is whatever we say it is that you owe and if you don't get down and lick my boots, you're going to jail". Under such circumstances, what businessman who had any choice would base his business here?
But where are you going to run? Increasingly the EU is unifying its tax laws and using its power to bully those countries which set lower tax rates. See what happened to Ireland, once a proudly independent nation, now reduced to an economic protectorate.