Mr David Trimble has criticised the terms of the forthcoming review of the Belfast Agreement. He says there should be a "George Mitchell-style" review of ongoing paramilitary activity, which he blames for the current impasse, followed by the "nuts and bolts-style" review suggested by the British and Irish governments.
His criticisms are contained in a letter seen by The Irish Times and sent to the Minister for Foreign Affairs, Mr Cowen, and the Northern Secretary, Mr Paul Murphy.
Dated December 23rd, it was drafted in reply to a joint invitation from the two governments to the UUP and other parties to submit ideas for the review, scheduled for this month.
Mr Trimble accuses London and Dublin of pandering to Sinn Féin, Alliance and the SDLP while "ignoring the more important concerns of the unionist community".
He also suggests some of the governments' ideas for the review, contrary to their claims, do address the fundamental aspects of the agreement. Any changes made would require legislation.
He also claims that in doing so the governments are acting beyond the scope of paragraph eight of the review section of the agreement which gives rise to this month's planned talks.
The UUP leader proposes a review along the lines of one carried out by Senator George Mitchell in 1999-2000, concentrating on the activities of paramilitaries and involving all the parties elected to the suspended Assembly in November.
He wrote: "I refer to the problem of continuing paramilitary activity and the failure, three and a half years after the due date, to achieve the decommissioning of all paramilitary arms.
"It is quite inappropriate to conduct the "nuts and bolts" paragraph eight review while ignoring the real problem, and it would be worse to artificially stretch that review to include that problem alongside a range of comparatively minor issues, which cannot be tackled in practice until the major issue is resolved."
A party spokesman told The Irish Times there was no question of the party not attending this month's review despite the clear misgivings contained in the party leader's letter.
Mr Trimble's criticisms became known as the International Monitoring Commission began its first full day in operation, having worked in shadow form since last year.
The commission is designed to determine if paramilitary ceasefires have been breached with a view to encouraging unionists back into a Stormont executive.
Sinn Féin is opposed to its formation, criticising it yesterday as "a sop to unionists". South Belfast Assembly member Mr Alex Maskey said it could be used by the British government to counter the democratic process and sanction elected republicans.
In a joint statement yesterday, the four commissioners welcomed the decision by the governments to exchange letters, thus empowering the new body.
Lord Alderdice, the Assembly's last speaker; Mr Joe Brosnan, former secretary general of the Department of Justice; Mr Dick Kerr, former CIA director general; and Mr John Grieve, former deputy assistant commissioner with London's Metropolitan Police, outlined their "primary purpose".
"The IMC has been set up as a result of the Joint Declaration of May 2003. It exists to help promote the establishment of stable and inclusive devolved government in a peaceful Northern Ireland."