The SDLP has said it would resist any new arrangements short of full power-sharing in Northern Ireland.
Interim proposals for a form of legislative Assembly without an executive including unionists and republicans have been outlined as a possible way of breaking the political deadlock.
But last night SDLP leader Mark Durkan condemned the idea being mapped out by Ian Paisley's Democratic Unionists and insisted his party would not consider it.
The Foyle MP said: "A two-stage process isn't open. If you start saying we are just going to go for a fallback, and then starting with a fallback . . . that is just holding back. Let's test it and see how far parties are willing to go."
The Stormont power-sharing administration has been suspended since an alleged IRA spy ring was uncovered more than three years ago, with direct-rule ministers committed to running Northern Ireland until all sides in Belfast can strike a new deal.
Northern Ireland Secretary of State Peter Hain has signalled the British government is prepared to consider setting up something short of the devolved executive laid out in the Belfast Agreement.
But Mr Hain, who is preparing to hold new political talks in February after the Independent Monitoring Commission ceasefire watchdog's next report on levels of IRA inactivity, stressed that the scheme must be temporary and win cross-party support.
"The end has got to be a power-sharing executive," he told the Sunday Times.
"The argument is whether you need an interim stage in order to get to that objective. "The parties have got to talk to each other. There's no point in saying 'take it or leave it'. That is not in prospect."
However, Mr Durkan emphasised the need to settle for nothing short of giving the Northern Ireland Assembly back its full powers.
He added: "We want the Assembly restored. If parties aren't willing to form an inclusive executive, we then have to look at what other options there are, short of suspension and direct rule again."