The Worldwide Disclosure Facility is the “final chance for those few still dragging their feet to put things right with any outstanding tax on undeclared offshore money or assets”, HMRC said.

The body revealed that 44 individuals acting as “professional enablers” are under criminal investigation for offshore offences.

This included independent financial advisers, scheme architects and promoters, chartered accountants, solicitors and chartered surveyors, officials stated.

In total, more than 90 individuals are under investigation by HMRC for with a total fraud value in excess of £748 million.

The online disclosure facility has provides evaders a “last chance to come forward and settle tax on their wealth hidden offshore” ahead of new data sharing arrangements and tougher penalties being introduced.

The WDF offers no special terms: those who come forward will pay the tax in full, with interest on top, with a minimum penalty of 30% of the tax due for evaders, and they could still face criminal prosecution.

The quality of the information disclosed will be taken into consideration.

From today, HMRC will also consider how long it has taken for someone to put their tax affairs in order when calculating penalties. This means that those who have delayed disclosing or ignored past opportunities will no longer get a reduction for disclosure.

This last chance comes before HMRC starts to receive an unprecedented amount of data on offshore accounts closing the net further on tax evaders, who are to be hit by tougher sanctions. This will be added to the offshore data HMRC receives year-on-year that is used to help settle hundreds of criminal investigations.

Jennie Granger, HMRC, director general of enforcement and compliance, said: “HMRC is getting even tougher on tax evasion. We relentlessly pursue tax evaders to ensure they pay every penny of the taxes and fines they owe, pushing for the toughest possible sanctions where appropriate.

“We’ve closed old disclosure facilities, increased penalties, and ramped-up our powers to tackle evaders and those that help others evade. Alongside this, international cooperation through global tax transparency is making it easier for us to catch evaders, as we increasingly receive more information about financial assets which people had hoped would remain hidden. Our message couldn’t be clearer: there are no safe havens left for tax evaders and no-one should be in any doubt that the days of hiding money offshore with impunity are gone.”

HMRC reported that it brought in £26.6 billion from tackling tax evasion and avoidance between 2014 and 2015, and since 2010, has raised over £2.4 billion from offshore evasion initiatives, including more than 10,000 disclosures.