The Ulster Unionist Party's deputy chief whip in the Assembly, Mr Derek Hussey, has expressed concern about the Hillsborough Declaration, saying that he has difficulty with the proposal to nominate Sinn Fein ministers before decommissioning occurs.
Mr Hussey is the latest in the UUP Assembly team to criticise the declaration. Another member, Mr Billy Armstrong, voiced his opposition earlier this week. And yesterday Mr Roy Beggs jnr said that he believed the language in the declaration was too ambiguous.
The criticisms will be a worrying development for Mr David Trimble. Anti-agreement and pro-agreement unionists are evenly divided in the Assembly, and the UUP leader cannot afford even one defection.
UUP Assembly members are to meet on Monday to discuss their approach to the multi-party talks, which resume the following day.
The Hillsborough Declaration proposes the nomination of ministers to the new executive followed by "a collective act of reconciliation", which would involve putting some weapons "beyond use", before the executive is formed.
Sinn Fein said on Thursday that the declaration was an attempt to rewrite the Belfast Agreement and called on both governments to revert to their original position.
Speaking yesterday, Mr Hussey said he did not rate the declaration's chances of success, particularly given Sinn Fein's "apparent move into the No camp". He said he had difficulty with the proposal to nominate Sinn Fein ministers before an arms handover.
He relayed his views to Mr Trimble at a private meeting yesterday.
The anti-agreement UUP MP, Mr Jeffrey Donaldson, said he understood the reservations that many in his party shared about the declaration. The language used by the two governments was "decidedly woolly" and unionists needed to know in clear, precise terms whether there must be actual decommissioning by the Provisional IRA before Sinn Fein was admitted into government.
Sinn Fein's stance on the Hillsborough Declaration was criticised yesterday by the SDLP. The party's negotiator, Mr Mark Durkan, said Sinn Fein should endorse the document.
The North's political development minister, Mr Paul Murphy, met members of the Progressive Unionist Party, the UVF's political wing, for talks at Stormont yesterday. Speaking afterwards, the PUP Assembly member for North Belfast, Mr Billy Hutchinson, said that his party was now entering "a period of reflection".
He would not comment on the UVF's statement this week that it would not be handing over any weapons in the immediate future even if the Provisional IRA decommissioned.
An Assembly member of the Northern Ireland Unionist Party, Mr Cedric Wilson, yesterday asked the Northern Secretary, Dr Mo Mowlam, to convene a meeting of parties not associated with paramilitary organisations in order to construct "a more viable and durable alternative to the talks process".