The DUP and Sinn Féin continued their prolonged negotiations at Stormont yesterday amid warnings that they were unlikely to strike a deal until late next month at the earliest.
According to Ulster Unionist leader Robin Swann, the assembly's two biggest parties will not forge agreement until after their party conferences.
Sinn Féin is due to hold its ard fheis in Dublin on November 17 and 18, while DUP members will gather at the La Mon hotel in Co Down hotel the following weekend.
Mr Swann said he could not envisage Arlene Foster going to her party's conference having signed an agreement that contained an Irish language act, while Gerry Adams was unlikely to try and sell his party a deal with no Irish language act.
The UUP leader repeated his call for the secretary of state to abandon mandatory coalition in the face of continued deadlock.
"Why should this country be held to ransom for the advantage of any political party?" he said.
"Sinn Fein's demands framed as rights cannot and should not be allowed to trump the rights of the sick and vulnerable – the government needs to step in and act now."
Meanwhile, the Stormont impasse provided the backdrop for clashes between Taoiseach Leo Varadkar and the Sinn Féin leader in the Dáil.
Mr Adams again referred to an Irish Times article earlier this month which claimed Sinn Féin northern leader Michelle O'Neill was overruled by her party leadership when she sought to strike a deal with the DUP.
The Sinn Féin leader accused the Fine Gael government of engaging in "untruthful, malicious and shameful" press briefings. Republicans have vehemently rejected the claim that Ms O'Neill was vetoed.
Mr Adams also criticised the British government for "indulging" what he called "stubborn elements within political unionism", which he blamed for obstructing an agreement.
But Mr Varadkar said he had no knowledge or interest in "disagreements or rivalries" that may exist within Sinn Féin.
He then accused Mr Adams of "setting the scene to ensure somebody else gets the blame for the failure to come to an agreement in Northern Ireland".
"You spoke about stubborn elements within political unionism - that's not a good way to talk about people you are trying to make an agreement with at the moment," the Fine Gael leader said.
"'Stubborn elements in political unionism', and then you attack the Irish government and then you attack the British government."
Mr Varadkar said his Sinn Féin counterpart's remarks did not sound like somebody who was trying to lead their party into an agreement with unionists, alongside the British and Irish governments.
"This sounds to me like somebody who has already given up and is already trying to spread the blame to others," he said.
Mr Adams insisted he would "never give up" and accused the taoiseach of offering "glib answers".
"These briefings on the part of your government were untruthful, malicious and shameful," he said.
The taoiseach's party colleague Simon Coveney was in Belfast yesterday for talks with the parties ahead of next week's deadline for concluding the latest round of negotiations.
The British government has said a deal must be struck before Monday in order to leave time to set a regional budget. In thw absence of agreement Secretary of State James Brokenshire is expected to bring forward the already-delayed budget.
