Nationalist politicians have said they don't see any significant shift in DUP thinking after Mr Peter Robinson said a new peace deal in the North supported by both communities was possible.
Sinn Féin admitted the DUP deputy leader was adopting a more "pragmatic approach" but the SDLP said the party had simply moved from a position of "huff and puff to fluff and bluff".
Addressing the Conservative Party's right-wing Monday Club in London, Mr Robinson said: "We do not wish to exclude nationalists from having a role in governing Northern Ireland but we cannot accept those who are linked to active terrorism ruling over those they continue to terrorise.Those who support or engage in such activity exclude themselves from the democratic process."
Mr Robinson said his party would force a renegotiation of the "fundamentally flawed" Belfast Agreement if it won 50 per cent of unionist seats in May's Assembly elections and blocked the election of a First and Deputy First Minister.
He said a new deal, supported by both unionists and nationalists, was possible.
The president of Sinn Féin, Mr Gerry Adams, said there did not appear to be anything significantly new in Mr Robinson's speech.
However, he said the party appeared to recognise that a considerable section of its community knew the "old DUP tactics" could not deliver effective and stable political institutions.
"Ian Paisley is probably too long in the tooth to change his approach to all of this," said Mr Adams.
"But I think Mr Robinson represents to some degree a more pragmatic approach because of the mood within unionism but not because of any 'road to Damascus' conversion by the DUP."
The SDLP leader, Mr Mark Durkan, said the DUP hadn't shifted from its core position. There had been "fevered speculation" about "all sorts of honeymoons between the DUP and Sinn Féin", he said.
"Let's be careful here. The DUP has at best moved from a position of huff and puff to fluff and bluff." The DUP was still refusing to work the Belfast Agreement and was demanding its renegotiation, Mr Durkan added.