The Northern parties are expected to be briefed today on the details of British legislation designed to enact the St Andrews Agreement.
The legislation will be published tomorrow, but party delegations are expected at Stormont today for a video conference with British officials in London.
The legislation was understood to be still under discussion last night, with officials from the British and Irish governments in close contact.
Measures are expected in relation to aspects of the administration of justice and policing, and the role and scope of ministers who are scheduled to take their seats around the Stormont Executive table in March.
One political source said: "Officials are still working away," but would not comment further.
A Downing Street source denied Sinn Féin members had held a meeting with Prime Minister Tony Blair but added that officials were continuing to discuss issues with the parties.
A Sinn Féin spokesman declined to comment other than to say: "We remain in contact with the two governments." One key demand, attracting cross-party support, could be addressed later today by a report requested by Mr Blair.
The Economic Research Institute is reported to have proposed that companies investing in the North receive an effective tax break on a significant proportion of their profits. Parties on all sides have called for the 30 per cent corporation tax to be brought into line with the Republic's 12.5 per cent level.
Chancellor of the Exchequer Gordon Brown, who met the parties two weeks ago in Downing Street to discuss a "peace dividend", has committed himself only to keeping the issue open. But he is known to be reluctant to offer a specific tax break to one region of the United Kingdom.
On another St Andrews-related issue, Stormont human rights minister David Hanson has opened a short period of consultation on the remit and membership of the bill of rights forum.
Establishment of the forum, and the tight timeframe for it to convene its inaugural meeting, was announced following discussions at St Andrews last month.
"I am confident that there is a momentum to take forward the important work on a bill of rights for Northern Ireland and I want to build on this by getting the forum set up quickly," he said. "In keeping with the arrangements announced at St Andrews, it is my intention that the forum should convene its inaugural meeting in December 2006 and I would therefore encourage all those who have an interest to let us have their comments promptly." Comment is invited before November 28th.