The two governments are considering a number of new ways of running the Northern Ireland Assembly, Taoiseach Bertie Ahern said today.
Mr Ahern warned that parties that did not support efforts to revive the North's political institutions could be left behind.
"We are looking at a number of models, not a lot of models, of what is the strategy to move forward and we would like to bring everybody with us.," the Taoiseach said.
"Our whole effort is to have an inclusive process based on the objectives and outcomes of the Good Friday Agreement.
"And if we can't bring everybody with us, then we have to make a call and move on. I'd still like to bring everybody with us but we can't wait around indefinitely."
Mr Ahern is due to meet a delegation from the SDLP in Dublin today. He met a Sinn Féin delegation yesterday in Government Buildings, where the party ruled out the possibility of a shadow assembly, open for business but with limited ministerial powers.
Sinn Féin president Gerry Adams will lead a delegation to Downing Street to meet Tony Blair today.
The shadow assembly, which the Rev Ian Paisley's DUP, has proposed, would serve as a debating chamber or could enable the 108 MLAs to scrutinise the work of Northern Ireland Secretary Peter Hain's ministerial team until full-blown devolution returns.
However, Sinn Féin and the SDLP are not keen on the idea, and there is suggestions that they could boycott such an Assembly.
Mr Ahern warned today that the process would move on even without the support of all parties.
"If we are forced that it can't be an inclusive process, and that for sure won't be the Irish Government's fault, but if somebody opts out, if more than one party opts out, then we have to find another way forward," Mr Ahern added.
"But that way forward will have to be as close as possible to the Good Friday Agreement."