Fianna Fáil Leader Micheál Martin has criticised Sinn Féin’s rejection of First Minister Arlene Foster’s proposals to recommence Stormont negotiations.
Sinn Féin's leader in the north Michelle O'Neill said establishing a powersharing administration that may collapse after a matter of months over the same problems would only fail the people.
The DUP leader called for a "common sense" solution appointing Stormont ministers alongside a time-limited process for making progress on the red line issue of an Irish language act and Ulster Scots.
Speaking today, Mr Martin said Sinn Féins should have considered the proposals.
“In our view, the Executive should never have been collapsed. Given the enormous challenge of Brexit and the other challenges facing the working people of Northern Ireland, the fact that there is still no Executive after eight months is disgraceful," he said.
“Sinn Féin’s leader in the north called for talks to recommence some weeks back, however, when a proposal was put to them last night they rejected it immediately.
“The ongoing stagnation in Stormont is impacting on people in Northern Ireland every day - and is most visible in the provision of health and education services. Indeed, politicians were powerless to do anything following the recent horrific flash floods in Derry.
Mr Martin continued: “We should remember that Sinn Féin initially collapsed the Executive because of the renewable heating controversy. Eight months later the issue has now changed to the enactment of the Irish Language Act.
“While Fianna Fáil supports the Irish Language Act, we do not believe that it should be used as a political pawn, when basic services for citizens are deteriorating."
Earlier today, Mrs O'Neill said: "This parallel process has been discussed and disregarded throughout the course of all the negotiations we have had to date."
She said the intervention demonstrated unionists had not listened to or acknowledged the reasons for Martin McGuinness' resignation from the head of devolved government which prompted its suspension earlier this year.
Mrs O'Neill said: "Establishing an Executive that may collapse after a matter of months on the same issues will only fail all our people.
"Let's agree to quickly conclude talks on implementation and rights, that is the only way to build a sustainable Executive that will last."
Powersharing has been in deep freeze since early this year when late Sinn Fein deputy first minister Mr McGuinness resigned in protest at the DUP's handling of a botched green energy scheme which risks landing the taxpayer in millions of pounds of debt.
Talks aimed at restoring the institutions are due to resume on Monday led by the British and Irish governments, with some prominent DUP MPs warning a return to direct rule from Westminster could be looming.
Sinn Féin claims the DUP has failed to embrace principles like equality and respect. The DUP argues that any deal should not be one-sided and devolution should be immediately restored to protect faltering health and education systems.
Dublin foreign affairs minister Simon Coveney said Mrs Foster's intervention was a genuine effort to show leadership and reach out towards compromise.
The DUP is propping up Theresa May's minority Conservative Government with support in key votes in exchange for a £1 billion spending package.
In a major speech in Belfast on Thursday night, DUP leader and Tory ally Mrs Foster said laws should be introduced to address cultural and language issues within a "time-limited" period.
She warned unless agreement can be found between the Stormont parties direct rule from London could be speedily reintroduced.
She said: "I am putting forward a common sense solution that can give us the Executive we need and resolve outstanding issues."
Mrs Foster called for ministers to return to posts so that decisions can be made and Northern Ireland can have a government again.
"But we also agree to bring forward legislation to address culture and language issues in Northern Ireland within a time-limited period to be agreed.
"If we fail to do that in a way that commands cross-community support then the Executive would cease to exist."