Round-table talks between all Northern Ireland’s major parties begin on Monday.
The British and Irish governments should end their “hands off” approach and forcefully drive negotiations to a conclusion, the nationalist SDLP said.
Politicians have been holding discussions since last month in a bid to break the long-running Stormont power-sharing impasse.
Northern Ireland Secretary Karen Bradley is due to update the House of Commons on progress later this week.
SDLP leader Colum Eastwood said: “If both governments continue to take a hands-off approach with this process, the DUP and Sinn Fein will carry on threatening to write the obituary of the Good Friday Agreement.
“Both governments need to wake up to the political reality that they are not bystanders in our politics.
“It is the authority and the balance provided by the two governments which ultimately underpins the politics of Northern Ireland.
“Their job is not alone to be facilitators of these talks. Their job is to be forceful in finally driving these negotiations to a conclusion.”
Mr Eastwood has called on the DUP and Sinn Fein to disclose what compromises they were prepared to make during a previous set of negotiations.
Former Stormont deputy first minister Martin McGuinness’s resignation more than a year ago in a row over the running of a botched green energy scheme left Northern Ireland without a devolved government.
An endless series of talks involving the local parties and the British and Irish governments has failed to break the deadlock.
Sinn Fein has called for an inter-governmental conference between the British and Irish to map a way forward.
The DUP wants to see the restoration of direct rule by ministers from Westminster.
Mr Eastwood called for a joint paper from the British and Irish governments outlining their view on a fair deal which could restore local government.