The Panama Papers have just exposed a top Conservative donor as a tax dodger.

David Rowland is one of Britain’s richest men. He’s donated more than £4 million to the Conservative party. Now it turns out that his business used a complex web of 126 companies to avoid paying any UK tax at all in 2014 -- and at the heart of that web are several companies based in Guernsey.

Tax havens in the British Isles should not be helping Britain’s super-rich corporations to avoid paying their fair share of taxes.

Let’s tell Guernsey enough is enough. It needs to introduce a public registry of beneficial owners of shell companies, now.

David Rowland’s company, Blackfish Capital Management, hasn’t done anything illegal. And that’s the problem. While the rest of us pay our way, rich corporations and individuals are legally allowed to hide behind anonymous “shell companies” based in tax havens to avoid paying their share.

Three years ago, David Cameron promised to take a huge step towards ending this sorry state of affairs. He pledged to get UK-linked tax havens like Guernsey to introduce to a public register of beneficial owners of companies, which would make it harder for wealthy corporations and individuals to avoid paying taxes.

The tax havens promised to look into it -- but so far, only one has taken action: Montserrat. Guernsey still hasn’t introduced the register. So the super-wealthy, like David Rowland, can keep using shell companies in Guernsey to hide their wealth.

It won’t be easy to end tax avoidance by Britain’s elite. But if we can get Guernsey to follow Montserrat’s lead, we will open the floodgates to real action from all of Britain’s Overseas Territories and Crown Dependencies -- and that would be a huge victory.

Let’s tell Guernsey: it’s time. Introduce a public register of company owners and help stop tax dodging.