Pat Finucane's family has pressed the British government to call a wider inquiry into their father's murder and consider calling Mrs Margaret Thatcher to give evidence.
Mr Finucane's sons and daughter issued their demand yesterday, adding weight to previous calls for a public inquiry into the lawyer's murder and calling on the Taoiseach to press Mr Tony Blair.
In a hard-hitting statement, Michael, John and Katherine Finucane said they had no faith in the Stevens inquiry, which is due to report to the Policing Board next month.
It was criticised on thegrounds that it was a police investigation when a broader inquiry was needed. Criminal prosecutions were not the answer, they said.
They alleged that state forces were involved in the case and that only a public inquiry could ascertain if those "at the pyramid of power" knew and approved of what was happening.
Mr Michael Finucane said Mr Blair's government was not involved in his father's murder, but unless he met their inquiry call, already endorsed by the Irish government, the SDLP, Sinn Féin and a range of human rights and lawyers' bodies, he was "part of the problem".
Such an inquiry could "rock the foundations of the British state", he added.
The British Prime Minister was accused of "borrowing the international integrity and credibility" of Judge Peter Cory, the former Canadian Supreme Court judge charged with assessing the evidence and advising on the next step.
Mr Finucane, himself a solicitor, held the British government accountable in the final instance, adding that the chain of command ran from the police and army through to Downing Street. As a result, British ministers could not stand aloof.
"Here in its own backyard it is being charged with the most serious crime a government could be charged with . . . assassination of its own citizens," Mr Finucane said.
The Finucanes' demand follows the BBC Panorama report which uncovered loyalist and intelligence service links to their father's murder.