Pressure is mounting for an independent judicial inquiry into allegations of collusion around the murder of Pat Finucane. Mr Martin McGuinness said yesterday the implications of the affair were "massive" and could confirm Mr Tony Blair's worst fears.
The Sinn Féin MP added: "This may be even bigger than Bloody Sunday, with wide-ranging implications for the British establishment. There is a very compelling case for the establishment of a public and international inquiry into what has been going on.
"I think the lid has now come off the can of worms and the worms are crawling out."
He accused the security establishment of malicious leaks against republicans to divert attention from the Finucane affair.
The SDLP said the controversy would have "a major emotional and political impact" because the contents of last night's Panorama investigation were "so chilling and graphic".
Mr Alex Attwood said: "The consequences of that, and the fact that it is going to be followed by the Stevens report which will add more detail and more substance over a much broader range than even these programmes, will confirm the need for an independent international inquiry."
The Northern Secretary has yet to comment. A senior political source at Stormont told The Irish Times last night that Dr John Reid would wait for publication of the Stevens report next month, rather than react to a TV investigation into what that report may say.
Unionists have reacted with varying degrees of hostility.
Lord Maginnis, the former Fermanagh-South Tyrone MP, said any allegations of collusion were serious. However, the RUC had its "bad apples" just as there were in the Metropolitan Police in London, the Greater Manchester and the West Midlands forces.
Mr David Trimble said he did not believe the RUC colluded with paramilitaries, although it was possible individuals may have.
However, the DUP again rejected the story, with Mr Sammy Wilson calling it the product of tittle-tattle from a paramilitary double agent with a chip on his shoulder.
Mr John White, a loyalist representative with an insight into UDA thinking, declined to comment.
Mr Ken Barrett, a former influential member of the UDA referred to by Mr Wilson, made a key admission relating to the Finucane killing to Panorama.
Relatives for Justice, a body representing some of those bereaved by paramilitary assassins during the Troubles, denied the killing of Mr Finucane was the result of any security force "rogue element".
The group said yesterday: "There is no doubt that collusion is an official policy that has included the RUC, British military and military intelligence" in a series of links which led to the British cabinet. "It is here that collusion was devised and sanctioned".
John Ware, the Panorama reporter, said last night he did not believe there was "a formal policy" of collusion to murder people - "not for one moment".
The Stevens investigation is understood to be close to finalising its report, but this could be affected by details unearthed by the BBC.
Mr Peter Cory, a retired Canadian Supreme Court judge, who will recommend if the case goes to a wider inquiry, is also beginning his assessment.