Relations between Peter Robinson and Martin McGuinness have been further soured after the Deputy First Minister accused some in the DUP of attempting to put the brakes on political progress.
Addressing the opening session of Sinn Fein's ard fheis in Wexford, Mr McGuinness said he believed that goodwill generated by the power-sharing deal with the DUP is being squandered.
He insisted he will not allow the issues in the Haass proposals – flags, parades and dealing with the past – to be pushed beyond the elections in May.
He also insisted he will not renegotiate the final text from the Haass talks, while Mr Robinson has said discussions must continue in a bid to reach agreement.
The DUP leader also referred to his Stormont counterpart as a "dictator" after Mr McGuinness claimed parts of the Orange Order, UVF and PUP in north Belfast were "one and the same".
Mr McGuinness told delegates in the city's Opera House that the potential of the Assembly and the Executive has not been fully realised.
"I think that much of the goodwill generated between ourselves and the DUP which saw the institutions established has been squandered as the result of a very deliberate strategy by some within that party who were uncomfortable first with the notion of sharing power with Sinn Fein and secondly at the relationship that developed between Ian Paisley and myself," he said.
"At a time when we should have been accelerating forward... some within the DUP sought to apply the brakes as they stood time and time again with the rejectionists and those opposed to power-sharing. I believe that was a huge mistake."
Mr McGuinness said there were senior people in the DUP who know the reality of the transformed situation in the province and that the Assembly and Executive were the only show in town.
He said that even before Dr Richard Haass and Professor Meghan O'Sullivan had chaired the recent talks he had concluded that issues like the past and parades, while important, could not be used to continually attack the political process. He said: "The Haass proposals as they currently stand represent a huge missed opportunity if they are not accepted by all the parties.
"Two months on from the proposals being published one big question remains unanswered –is political unionism up for doing a deal or not?"
To applause from the delegates, Mr McGuinness went on to ask whether agreement will be subject "to the whim of the Orange Order... extreme loyalism or mavericks who shout the loudest from the sidelines but hardly have a vote to their name".
The Deputy First Minister also turned his attention to dissident republican groups amid reports of what he called a "developing debate on moving away from armed action".
Mr McGuinness said the growing public expression against violence by republican groups opposed to the current peace process was to be warmly welcomed.
He said: "We have said for a long time that dialogue with other republicans and across all strands of national and democratic opinion is an essential part of engagement.
"Militarist actions by a few small groups will only set back the progress being made towards a united Ireland.
"They should stop their activities immediately."
The party's national chairman Declan Kearney said that some within unionism were very angry because they perceived they had been disadvantaged by the peace process.
"They are seized by a fear.
"Fear can be real or imagined but it needs to be heard and addressed when it exists," he said.
Mr Kearney also said some sections of political unionism did not want to compromise on anything.
Gerry Kelly said unionists must realise that it was better to reach a deal sooner rather than later, and perhaps for their own sake.
WHAT HE SAID ABOUT...
Dissidents: "In recent times I have met with anti-peace process elements, both republican and loyalist, to argue for an end to their activity. I restate our willingness to engage with these groups."
Unionists: "I want to appeal to ordinary unionists out there who believe in the peace process, who want to see a better future built for our children, to make your voices heard and to embolden your political leaders to do the right thing and build a shared future together on the basis of equality and respect."
Flags and parades: "The time for agreement is not after the May election nor after the marching season – the time for agreement is now."
In a recent interview, Martin McGuinness said three-quarters of DUP MLAs won't acknowledge him when they pass him at Parliament Buildings. The Belfast Telegraph asked a cross-section of DUP members if this was really true
By Rebecca Black
"My business at the Assembly is to carry out the work I have been elected to do on behalf of my constituents. I am not there for to have conversations with elected members of Sinn Fein.
"I am not prepared to commence doing that."
Thomas Buchanan (West Tyrone)
"It's not something I've ever thought about. I don't know where that's even come from. I have quite a healthy working relationship with the Sinn Fein MLAs I work with on committees so I am not sure where Martin McGuinness' comments have come from."
Paula Bradley (North Belfast)
"There is a working relationship with the man. We're not going to be friends. I can't wipe out the memory that the organisation which he openly admits to being a member of was responsible for the murder of my cousin. It's never going to happen."
Jonathan Craig (Lagan Valley)
"I think all of this is a little off the wall.
"He's not a bosom buddy, but if I saw him in the corridor I'm not the sort of person to snub anyone.
"You pass the time of day and that's it.
"There is business that has to be done, and if business has to be done you have to speak to them (Sinn Fein).
"It's business-like and that's all."
Paul Girvan (South Antrim)
"I would nod at him out of courtesy but I wouldn't stop for a conversation. I think he needs to do more, there is no doubt that when the pressure comes on he backs into his own corner.
"There are a lot of issues that need dealt with. Sinn Fein MLAs are there to represent their people, I am there to represent mine. On committees there is a fairly good working relationship between us."
William Irwin (Newry/Armagh)
"No comment. I think the Belfast Telegraph should have better things to do with their time than this."
William Hay (Foyle)
"Martin McGuinness is not the best person to be lecturing anybody on courtesy.
"His past will keep haunting him."
Maurice Morrow (Fermanagh/South Tyrone)
"There's a lot more important things to be getting on with."
David McIlveen (North Antrim)
"I am not in Stormont to be friends with Martin McGuinness. I am there to do a job and be professional. If I have to do work with Martin McGuinness I will do it, but I am not there to be his friend."
Adrian McQuillan (East L'derry)
"DUP MLAs have a working relationship with Sinn Fein via the various committees to deliver the Programme for Government."
Robin Newton (East Belfast)
"Relationships are fine. This is a daft conversation and really there are a lot more important political issues to be highlighting."
Alastair Ross (East Antrim)
"I could comment, but I won't. The party will respond, it isn't up to individual MLAs to comment."
Mervyn Storey (North Antrim)
"Inquiries like this should be directed to our Press office."
Peter Weir (North Down)