SDLP leader Colum Eastwood has said that the Irish and British governments should publish their proposals to revive power-sharing in Northern Ireland if no deal is done this week.
Mr Eastwood said the governments should set out fair, compromise solutions to the deadlock if the Democratic Unionists and Sinn Féin do not come to agreement.
Major blocks to getting Stormont back up and running include republicans' demands for a standalone Irish language act to give formal rights to speakers.
There are also issues around so-called legacy investigations relating to the Troubles.
As power-sharing negotiations resume in Belfast, Mr Eastwood said that as crises build in health and education it is not credible or sustainable to leave success of the talks in the hands of the DUP and Sinn Féin.
"We acknowledge that these parties have the big mandates from the electorate but they do not have a mandate to hold the North ransom in a position of permanent stalemate," the MLA for Foyle said.
Ministers have not sat at Stormont for seven months, after the late Martin McGuinness resigned as deputy first minister in a row over the DUP's handling of a botched green energy scheme.
Mr Eastwood said that if it becomes clear that the two big parties cannot do a power-sharing deal then the governments should make their joint proposals public.
"They should then publicly challenge all the parties to sign up to it or reject it," he said.
"This intervention by the co-guarantors of our political agreements would also bring focus to the real priority of finally getting a government formed which can begin to tackle hospital waiting lists, school budget cuts and the growing numbers of families without a home."
Mr Eastwood also questioned whether the DUP's and Sinn Féin's signals in the last week that they were keen to engage in talks are as much about avoiding blame if talks collapse.