The responsibilities of the North's 12 former ministers have been divided up between British government ministers following the suspension of the Stormont Executive and the reintroduction of direct rule from Westminster. The Northern Secretary, Mr Peter Mandelson, will acquire the duties of the former First Minister, Mr David Trimble, and Deputy First Minister, Mr Seamus Mallon.
When Westminster devolved powers to the Northern Ireland Executive last year, only three government ministers remained at Stormont: Mr Mandelson; the Security Minister, Mr Adam Ingram; and the Northern Ireland Office Minister, Mr George Howarth.
Mr Ingram will acquire the responsibilities of five of the former Northern Ireland ministers: Trade and Industry; Agriculture; Finance and Personnel; Higher and Further Education and Training; and Regional Development. Mr Howarth will take responsibility for Health, Education, Culture, Social Development and Environment.
Although the reintroduction of direct rule will mean considerably extra work for Mr Mandelson, Mr Ingram and Mr Howarth, a Northern Ireland Office spokesman said he was unaware of any plans to move more British government ministers to Belfast.
It is understood the North's 12 former ministers will have their salaries suspended and will lose their office facilities, ministerial cars and other perks.
The Northern Ireland Office source said the matter was being dealt with "sensitively". The former ministers are expected to begin moving out of Parliament Buildings, Stormont, later this week.
It is understood the salary of Assembly members will fall by £9,000 from £38,000 to £29,000, a return to pre-devolution levels. However, it is expected that non-elected members of the cross-Border implementation bodies will continue to be paid.
Sinn Fein has threatened to mount a legal challenge to the suspension of the North's political institutions. However, a Northern Ireland Office spokesman said the British government was confident of the legality of the move.