Unionists demanded to know yesterday whether a secret deal had been struck with Gerry Adams to allow fugitive IRA terrorists back to Northern Ireland in return for Sinn Fein endorsing the police.

As Sinn Fein’s executive backed Mr Adams’s proposal for a special party conference on the issue, Ian Paisley’s Democratic Unionists asked what concessions had been granted to the Sinn Fein leader to ensure republican support for the Police Service of Northern Ireland.

Lord Morrow, the Democratic Unionist chairman, said: “Unionists today are asking the question, what further concessions has Government given in return for this latest statement by Adams? On the Runs has been one of Sinn Fein/IRA’s demands for movement. Are we now to accept this has been delivered?”

In a statement on Thursday, Mr Adams called for a Sinn Fein special conference — or ard fheis — to be held next month with a view to ending the party’s historic opposition to police in Northern Ireland.

Although he said that such a move would be difficult for many nationalists and republicans to accept, he added: “However, the achievement of a new beginning to policing, as promised in the Good Friday agreement, would be an enormous accomplishment. And I believe that we have now reached the point of taking the next necessary step.”

Last night, after a six-hour meeting of the party’s 56- strong executive in Dublin backed the idea by a two-thirds majority, Sinn Fein said that it would be holding a special conference on policing, provided that there was a positive response to the initiative by the British and Irish governments and the DUP.

Under the terms of the St Andrews agreement in October, republicans must fully support the police and the rule of law before devolution can be restored to Northern Ireland. Unionists must show that they are genuinely committed to sharing power with republicans.

If accepted by Sinn Fein’s rank-and-file, a decision to support the police would be the most fundamental shift in mainstream republican ideology since an ard fheis voted in 1986 to end its policy of not taking seats in the Irish parliament. Peter Hain, the Northern Ireland Secretary, described Mr Adams’s statement as “a seismic step”.

The British and Irish governments have named March 7 as the date for fresh assembly elections and hope that a new executive will be functioning by March 26. Talks aimed at restoring the Stormont Assembly and its executive have continued since negotiations at St Andrews finished without a concrete deal between Sinn Fein and the DUP, but rather a “roadmap” setting out a timetable for achieving this.

The prospect of on-the-run IRA terrorists being allowed to return to the Province without having to face jail is difficult for Unionists to stomach. Controversial legislation allowing this to happen was dramatically pulled this year after widespread opposition.

However, Unionists remain suspicious that No 10 has rekindled this idea as part of behind-the-scenes negotiations with Mr Adams. Jeffrey Donaldson, the DUP’s MP for Lagan Valley, gave a cautious welcome to Mr Adams’s statement but em- phasised that “words needed to be matched by deeds”.

Sir Reg Empey, leader of the Ulster Unionists, said: “The key to all of this is, what decision is the ard fheis being asked to endorse? Is it a qualified decision with power to be handed to the leadership to handle?"

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