The British government is prepared to lift the bar on members of the Oireachtas serving in the British House of Commons and the Northern Ireland Assembly.
Whitehall sources said publication of a Home Office Bill amending the House of Commons disqualification provisions was imminent.
At the same time, 10 Downing Street confirmed that Commons rules could be changed to enable the Sinn Fein MPs, Mr Gerry Adams and Mr Martin McGuinness, to enjoy office facilities at the Palace of Westminster without having to swear the oath of allegiance to Queen Elizabeth.
The expected Home Office move - which will have no bearing on the oath - is the latest piece of parliamentary choreography resulting from the establishment of the institutional frameworks provided by the Belfast Agreement. The parliamentary bar was used to force Mr Seamus Mallon from his seat in the 1982 Stormont Assembly because of his membership at that time of the Seanad. And the proposed change in the law will be seen as a deliberate move by the British government to facilitate Sinn Fein's electoral strategy, and to avoid a re-run of the Mallon court case when, as expected, leading Sinn Fein figures seek election to Dail Eireann.
Discussions are under way to facilitate a possible change in House of Commons rules to enable Mr Adams and Mr McGuinness to take up their office facilities at Westminster without swearing the oath of allegiance, Downing Street confirmed yesterday.
Any change in the rules would almost certainly require the approval of MPs in the Commons and is likely to meet with opposition from some Ulster Unionists and Conservative MPs.
There are however, no plans to change the rule that requires MPs to swear the oath of allegiance so that they can take their seats in the Commons, speak in the chamber and draw a salary.
Mr Blair's official spokesman said active consideration was being given to break the deadlock which has seen Mr Adams, the MP for West Belfast, and Mr McGuinness, the MP for Mid-Ulster, barred from being allocated office space at Westminster because of their refusal to swear the oath.
"I am aware that there are discussions about the issue. The issue is being looked at. It is quite complicated. I think it would require a resolution of the House," the spokesman said, but it is not expected that the rules would be changed this year.