Sinn Fein has forced the Democratic Unionists to accelerate the devolution of policing and justice powers from Westminster, rival unionists claimed today.

Ulster Unionist leader Sir Reg Empey said the deal unveiled by the two parties this week amounted to Sinn Fein "bringing the DUP to heel".

Sir Reg's comments came after his party last night agreed a new electoral pact with the Conservatives which he said would allow unionist voters to strengthen UK links.

"Our main aim is to give us a genuine link into the politics of the rest of the UK," Sir Reg said today.

"When we have for years had others building with the South (of Ireland), we need to build real political links with the UK."

The deal will initially see the parties run on a joint ticket in Westminster and European elections in Northern Ireland, though it is yet to be decided whether the partnership would extend to Assembly and local council polls.

Representatives from both parties will now form a joint committee to work out an electoral strategy ahead of next year's European elections, with a report due at the end of January.

Sitting Ulster Unionist MEP Jim Nicholson will be the first to stand on the joint ticket.

Today it was confirmed he had been named the Conservative Regional Affairs spokesman for the UK at the European parliament.

The DUP's David Simpson said Conservative leader David Cameron had pledged to contest every Westminster seat in Northern Ireland.

But Mr Simpson said splitting the unionist vote ensured nationalists and republicans would hold South Belfast and Fermanagh/South-Tyrone.

But Sir Reg dismissed the DUP charge and said it had stood against Ulster Unionist candidates or backed rival unionists in the same seats before.

"Mr Simpson should remember the DUP were the original vote splitters from when they were formed in the 1970s and all that unfolded after that," said Sir Reg.

He added: "I am always ready to talk to people about how we maximise unionist representation, but Mr Simpson has to recognise his party's guilt in this matter."

Sir Reg said it was too early to say if current UUP candidates would have to make way in some constituencies for prospective MPs drawn from Conservative ranks.

On Tuesday First Minister Peter Robinson and deputy First Minister Martin McGuinness unveiled a deal on the devolution of policing and justice powers.

It ended a five month stand-off during which Sinn Fein blocked Executive meetings in protest at what it said was DUP failure to deal with issues of importance to republicans.

The agreement does not set a date for the transfer of powers, but Sinn Fein said it believed the DUP would deliver on the process.

Sir Reg said: "I have no doubt it will happen. Policing and justice is going to happen.

"It has clearly been accelerated by Sinn Fein.

"They have taught the DUP the lesson that Stormont cannot work without them."

The Ulster Unionist leader rejected DUP claims they had remained true to their manifesto pledges by preventing Sinn Fein taking the justice ministry and by ensuring building community was central to the deal.

"The comments we have had from people like Nigel Dodds...it is hooey," said Sir Reg.

"Do they think that people are stupid altogether?"

He said that if the DUP did not deliver on the deal, Sinn Fein could again frustrate the work of government.

Sir Reg said: "I think that some of his people think Peter Robinson is Prime Minister, (but) he is equal First Minister with Martin McGuinness.

"Sinn Fein have brought the DUP to heel."

DUP Assembly member Michelle McIlveen said: "Reg Empey is in no position to criticise over the devolution of policing and justice."

She said that had it not been for the DUP, the powers could have been devolved by now under the terms of the d'Hondt power-sharing mechanism, which would have opened the possibility of a Sinn Fein minister.

Ms McIlveen added: "His record on policing and justice stinks."

On the UUP's tie-in with the Tories, she hit out at a Conservative Party member who had branded the Orange Order "backward facing" and said the new alliance would not benefit unionism.

"The way in which unionism can best be advanced and protected is through winning friends in all parties at Westminster," she said.

"I know that there will be many members of the UUP who will be searching their souls today because of what Reg Empey has done.

"I would remind them that the DUP is actively working to unite the unionist community and further secure Northern Ireland's place inside the United Kingdom."

The Alliance Party's Stephen Farry questioned the rationale of David Cameron's Conservatives.

"After wandering in the wilderness looking for a new identity, and alliances from the UVF-linked PUP to the SDLP, Reg Empey's Ulster Unionists have now formed two electoral pacts in the past few weeks, one with Jim Allister's TUV (Traditional Unionist Voice) and the other with David Cameron's Conservatives," he said.

Mr Farry said the UUP had agreed to advise supporters to transfer votes with the hard-line TUV, which wants an end to power-sharing with Sinn Fein, in the European elections next year.

The Alliance spokesman said: "For the Conservatives, this seems a truly bizarre move. David Cameron was supposedly trying to modernise his party into a progressive force, fit for government.

"Through this pact, he has linked his party to identity politics and tribal headcounts rather than dealing with the issues and building a modern, shared society.

"In particular, the Conservatives become part of the same electoral pact for the European Election as (TUV leader) Jim Allister. This pact has turned the European Election not into a contest about how best to secure Northern Ireland's interests in Europe, but a sectarian headcount.

"The Conservatives are now signed up to a message that what matters above all else is that unionists are returned in elections irrespective of the issues."