David Cameron has written to the leaders of Britain's offshore tax havens stressing the need to "get our own houses in order" as he pushes for international action to tackle avoidance schemes.
In a message to 10 crown dependencies and British overseas territories Cameron said he backed their right to be low tax jurisdictions but insisted that rules needed to be set and enforced fairly.
The move comes ahead of next month's G8 summit in Northern Ireland, where Cameron will push for an agreement aimed at clamping down on tax evasion and avoidance.
He said he wanted the G8 to "knock down the walls of company secrecy" to reveal who really owns and controls firms.
Cameron's initiative came as he prepared to raise the issue of corporate tax dodging with Google's boss, Eric Schmidt at a meeting in Downing Street.
The internet fim's executive chairman is a member of Cameron's business advisory group, which has its regular quarterly meeting on Monday, just days after Google was given a mauling by a House of Commons committee over its tax affairs.
The group holds its meetings behind closed doors and Downing Street does not reveal the content of its deliberations but a source inside No 10 confirmed that tax will be up for discussion, insisting that "nothing is off the table" when Cameron meets the group of 16 business leaders.
The PM's letter calling for more transparency about tax information and the ownership of companies was sent to leaders in Bermuda, the British Virgin Islands, the Cayman Islands, Gibraltar, Anguilla, Montserrat, the Turks and Caicos Islands, Jersey, Guernsey and the Isle of Man.
Cameron wrote: "As you know, I have made fighting the scourge of tax evasion and aggressive tax avoidance a priority for the G8 summit which the UK is hosting next month.
"With one month to go, this is the critical moment to get our own houses in order. I am looking to all the overseas territories and crown dependencies to continue to work in partnership with the UK in taking the lead on two critical issues: tax information exchange and beneficial ownership."
He told the leaders: "I respect your right to be lower tax jurisdictions. I believe passionately in lower taxes as a vital driver of growth and prosperity for all.
"But lower taxes are only sustainable if what is owed is actually paid – and if the rules to achieve this are set and enforced fairly to create a level playing field right across the world. There is no point in dealing with tax evasion in one country if the problem is simply displaced to another."
He welcomed commitments made by the territories to exchange tax information but said there was also a need to improve its quality and accuracy.
"Put simply, that means we need to know who really owns and controls each and every company," he said.
"This goes right to the heart of the ambition of Britain's G8 to knock down the walls of company secrecy.
"Some of you have already led the way with public commitments to produce action plans on beneficial ownership – and I hope those who have yet to can do so as quickly as possible.
"Getting the right content in these plans will now be critical. These will need to provide for fully resourced and properly managed centralised registries, that are freely available to law enforcement and tax collectors, and contain full and accurate details on the true ownership and control of every company."
Ed Miliband has pledged to write new rules to tackle corporate tax dodgers if he wins the next election, even if there is no international consensus for action.
In an interview with the Observer, he said Cameron's government was "dragging its feet" on the issue.
