SINN Fein has denied Democratic Unionist Party claims that calls for renewed Stormont talks are a “stunt”. The power-sharing Northern Ireland Assembly broke down in January amid continued controversy about DUP leader Arlene Foster’s role in the so-called “Cash for Ash” scandal.

Bungled payments in the renewables scheme are expected to cost the taxpayer around £500 million.

A March election triggered by the resignation of then-deputy first minister Martin McGuinness saw his party, Sinn Fein, and Foster’s DUP returned as the two largest parties, but the sides have been unable to form a coalition.

Key issues include same-sex marriage, an Irish language act and measures to tackle the legacy of the Troubles.

Talks between the parties were postponed for the summer after they failed to reach agreement.

On Sunday, Michelle O’Neill, leader of Sinn Fein in Northern Ireland, wrote to the UK and Irish governments as well as the heads of rival parties calling for negotiations to resume next Monday.

However, senior DUP member Simon Hamilton called this a “stunt” and accused them of stalling progress.

The MLA for Strangford told BBC Radio Ulster: “The DUP would go up to Stormont this morning and form a government and deal with those difficult issues that there are around health, around education and the economy which we believe are more important than the issues which on which Sinn Fein are stalling the restoration of an executive.

“They are the only party that are blocking the restoration of an executive to deal with those difficult issues and there are many who are coming to the conclusion that Sinn Fein do not actually want to go back into government, that they are not serious about restoring devolution.”

The comments came before a visit to Dublin by Northern Ireland Secretary James Brokenshire today, which is expected to take in talks with Ireland’s Foreign Affairs Minister Simon Coveney on the Stormont deadlock.

Yesterday O’Neill said: “It’s not a stunt. What it clearly is about is trying create a bit of momentum, trying to kick-start a process. I have heard James Brokenshire saying that he wants to resume things before the end of the summer, but it needs to happen now.”

Hamilton called for the immediate formation of a new executive at Stormont, with parallel talks to deal with the issues at the centre of the rift.

However, O’Neill said: “What we’ve had is a failure from the DUP to deliver on people’s rights, to deliver what they’ve previously signed up to. I don’t think it’s tenable that you can have an executive while we see those issues outstanding.”

Clare Bailey of the Green Party said: “Since the last election, my office has been empty and a lot of MLAs are the same. We don’t know whether we should move into our offices again. It is like a ghost town.”