Britain is preparing to launch a legal challenge against America over its use of the death penalty - a move which could held save the life of a Bermudian-born man.

Tracy Housel, 42, who was born a British citizen in Bermuda, was convicted of beating and strangling to death a woman in Georgia.

He was sentenced to die in 1985 and could be executed this year.

Last week his lawyers applied to the US Supreme Court in an 11th-hour bid to save his life.

They argued that he was suffering from a mental illness at the time of the crime and may have been badly advised by his lawyers about his guilty plea, Britain's The Independent newspaper reported yesterday.

In an unprecedented move the Foreign Office will instruct lawyers to intervene in an attempt to halt the executions of Housel, who was born to American civilians working on the Kindley Field US base, and another man with dual British and US nationality, currently on Death Row.

Housel left Bermuda a year after his birth.

Britain is also considering taking a case to the International Court of Justice in The Hague to challenge America over its death penalty policy.

Ministers are known to have serious concerns about the trials of both Housel and a second man, Jackie Elliott, 41, who denied but was convicted of the rape and murder of an 18-year-old woman 15 years ago.

Washington is understood to be angry that the Foreign Office should choose to act on two Death Row cases involving American subjects who only acquired British nationality by an accident of birth.

But a spokeswoman for the Foreign Office said yesterday that the former foreign secretary Robin Cook had made clear earlier this year that government policy was to express Britain's "strong opposition to the death penalty and its imposition on British nationals".

She said people either had the right to British nationality or they did not - there was no halfway position.

Lawyers acting for Housel say the tougher stance adopted by the British Government represents an important step forward.

Until now the Foreign Office has refused to intervene in American death penalty cases until all judicial avenues have been exhausted.

Housel's lawyers, Hugh Southey, a barrister at Michael Mansfield's chambers in London, and Yasmine Waldje, a solicitor at the City law firm Lovells, have had urgent meetings with Foreign Office officials to try to get the Government to take unprecedented steps to save their client's life.

The Foreign Office said that before its lawyers formally intervened in the cases it would continue to use diplomatic channels to help to secure a reprieve for both men.

"We are to make diplomatic representations on behalf of Housel and are considering the best way forward in the case of Elliott," the spokeswoman said.