The British government is showing exasperation with the SDLP and Sinn Fein, and to a lesser extent with the Irish Government, over policing. As the final stages of the Police (Northern Ireland) Bill are enacted in Westminster, the brinkmanship of the key protagonists is becoming increasingly dangerous.
British sources argue nationalists are making demands that would undermine Peter Mandelson's "sovereign" role in Northern Ireland, while nationalists say they "want Patten because Patten is the compromise".
Nationalists complain Mr Mandelson is working to what Sinn Fein calls "the securocrat agenda". The central issue here is that of accountability, or the power and role of the Policing Board, the police ombudsman and the oversight commissioner.
The SDLP and Sinn Fein contend that the powers they want extended to these bodies, in line with Patten, are not of alarming concern to unionists, but do terrify British army chiefs, the Home Office, MI5 and MI6 - "the securocrats".
Mr Mandelson believes nationalists are making unreasonable demands. His annoyance was reflected in his put-down of Patten commission member Prof Clifford Shearing, who claimed the British government had "gutted" Patten. Prof Shearing should "live in the real world", said the Northern Secretary.
All sides agree there has been a narrowing of the differences. The problem is that the British government says there can be no more changes to the Bill while nationalists complain serious matters remain unresolved.
According to British sources there is a fear that republicans in particular would exploit the Policing Board and the office of the police ombudsman to "rub unionist noses in the ground".
The British government appears to believe nationalists are not properly appreciative of the unionist perspective on Patten.
One London insider said the Bill provided for a far greater degree of police "accountability and transparency" than could be found anywhere in Britain or the Republic. "But these powers were never intended to set up witch-hunts into the past," he added.
He said there was a fear Sinn Fein might set in train a litany of inquiries into past actions by the RUC. "We could have a bear pit focused on the past rather than have the focus on the future," he said.
Patten proposes that the oversight commissioner should have responsibility for "supervising" the implementation of the commission's recommendations, but while the British government envisages him overseeing the reform he could not have "extra-parliamentary powers".
"He cannot be above parliament - that cannot happen in any democracy," added the source.
A Sinn Fein spokesman described the "witch-hunt" argument as "bogus" and a British attempt to "muddy the waters" over its reluctance to allow the creation of a truly accountable police service.
The SDLP Assembly member, Mr Alex Attwood, said there was no question of his party trying to exploit the Policing Board or the ombudsman to create "an ad-hoc truth and reconciliation commission looking into past actions of the RUC".
But Mr Attwood added that the Policing Board should have the power to "deal with the past where it was relevant to the future". The SDLP and Sinn Fein also claim the Bill has diluted the powers of the board to hold the chief constable accountable.
From a nationalist standpoint, progress has been made on the emotive issue of the police name. In the House of Lords last week the Labour junior minister Lord Falconer insisted the new name, the Police Service of Northern Ireland, "will be used for all operational and working purposes, including whenever and in whatever circumstances the police interface with the public".
On the badge and the British union flag flying over police buildings, Mr Mandelson wants the Policing Board to find a solution. But it's a fair bet that the 19-member board of nationalists unionists and independents won't achieve a consensus on the name without some serious prodding.
The final shape of the Bill, which is due to receive royal assent at the end of this month, has the potential to trigger a positive or negative domino effect that could be absolutely crucial to the future of the Belfast Agreement.
If a policing system can be established which is broadly acceptable to the entire community, then the impasse over IRA arms and Sinn Fein ministers attending North-South Ministerial Council meetings could be resolved. If policing is not resolved, then we face political gridlock and the probable review and suspension of the institutions of the agreement.
The British government says the time for talking is now over. "We are where we are. We believe we have the balance right," said a British source, but the Irish side says negotiations will continue to the bitter end.