Northern Ireland's First Minister Peter Robinson tonight demanded changes to Richard Haass' proposals to deal with contentious flags, parades and the country's troubled past.
As all sides in Belfast prepared for new rounds of intensive discussions before final recommendations are presented by Christmas, the Democratic Unionist Party (DUP) leader said he could not agree to any of the papers on the talks table and claimed matters seemed to be moving backwards on flags.
"Nobody is throwing the towel in at this stage. We are just saying that there is not a set of proposals that we can support, agree to or recommend," he said.
Mr Haass, a former US diplomat, is in London today to meet Northern Ireland Secretary Theresa Villiers ahead of further five-party talks later this week.
But it was clear Mr Robinson, who represents Northern Ireland's largest party, was unhappy with proposals before the parties.
"There are some things that are totally unacceptable and we would be outraged if we really believed that Dr Haass was serious in believing that that was going to be an outcome," he said.
"I suspect that Dr Haass, like everybody else, is hearing views from a wide range of people and putting some of their comments within the papers to allow people to react, well, he is going to get a reaction."
He said some of the experienced foreign policy expert's suggestions were still unacceptable to the DUP and very considerable work had still to be done to mend the "inadequacies".
Parades by members of the loyal orders and republicans, the flying of flags and the legacy of the region's 30-year conflict are issues which were not resolved by the peace process or the 1998 Good Friday Agreement, which largely ended violence responsible for more than 3,000 deaths.
Mr Haass, a former envoy to Northern Ireland during the Bush administration, has spent weeks in discussions in Belfast, London and Dublin after he was enlisted to submit recommendations to the ministerial Executive at Stormont.
The five party Executive, while a coalition, is dominated by the DUP and Sinn Fein. The Ulster Unionists, nationalist SDLP and centrist Alliance Party make up the other governing partners.
The Executive is resolute that an upsurge in recent dissident republican violence will not shake it but has made few key decisions in recent months following a loyalist summer marching season pockmarked by violence and amid unionist concern that senior Sinn Fein MLAs have glorified the past deeds of the IRA, combined with sharp differences over whether the guilty should be brought to justice for Troubles crimes.
Loyalists have fought sporadic but fierce pitched battles with police over truncated marches and during protests against the decision to restrict the flying of the Union flag from Belfast City Hall a year ago.
Mr Robinson did not disclose details of the negotiations but claimed they had gone backwards on flags. He said hopes for progress on all issues remained.
"If I though that was the final paper there would be steam coming out of my ears," he added.
"But it is not the final paper and we still have work to do and we are up to doing that work."
Sinn Fein Deputy First Minister Martin McGuinness took to Twitter.
"Let's prevent the paint lifting off the wall. The more excitable amongst us should cool their jets," he said.