Hardline unionist Jim Allister crossed swords with the Speaker in the Assembly just minutes after William Hay was restored to office.

Mr Allister was repeatedly asked to resume his seat in clashes which marred the opening day of the new session.

The spat followed a significant move when, in a sign of increasing co-operation between the DUP and Sinn Fein, Mr Hay (right) was formally nominated for the Speaker’s position by Martin McGuinness.

Traditional Unionist Voice leader Mr Allister said the nomination by “Sinn Fein/IRA” demonstrated “another sordid deal” between the DUP and Sinn Fein.

An agreement between the two main parties means the Assembly will get its first nationalist Speaker in three years — which Mr Allister described as a “new depravity” for Stormont.

He also called former Sinn Fein junior minister Gerry Kelly “bomber Kelly” — a reference to an IRA car bombing in London in 1973.

And he referred to allegations made in the House of Commons by DUP MP David Simpson about Francie Molloy.

Upper Bann MP Mr Simpson was a former MLA, but stood down from the Assembly in the last term to concentrate on the House of Commons. Yesterday Mr Allister asked the packed DUP benches: “Was he (Mr Simpson) telling lies?

“Was he telling the truth?

“Or do they just not care?”

Mr Allister also said Mr Hay had “brought no credit” on himself or Stormont by some decisions in the last Assembly which “blocked the truth” and were pro-Sinn Fein.

After the Speaker twice asked the former DUP man to sit down, Mr Allister challenged Mr Hay to set out the reasons why he had been called to order.

Mr Hay said Mr Allister was coming close to challenging the authority of the chair “and I would not go there”.

Mr Allister said he would support the other Stormont Deputy Speakers, Roy Beggs of the Ulster Unionists and John Dallat of the SDLP, because they were “untarnished democrats”.

The row was followed by the formal election of First Minister Peter Robinson and Deputy First Minister Mr McGuinness. “This new Assembly gives us the chance of a fresh start with a renewed mandate,” said Mr Robinson. “Let us use it to create the new Northern Ireland.”

Turning to the anti-Agreement forces of dissident republicanism and Mr Allister, he added: “I want to make it clear that there are those outside who think that they can disturb the will of the people through terrorism, and there might even be some inside who think that they will do it by political means.

“To all of them I say: ‘I'll be a thorn in the flesh of anyone who would try and disrupt the democratic will of the people of Northern Ireland'.”