The former junior minister at the British Home Office, Mr George Howarth, is expected to arrive in Belfast on Monday to take up his new posting in the Northern Ireland Office.
The new member of the Northern Ireland team was last night welcomed to the position by the Northern Secretary, Dr Mo Mowlam, who retained her post in Mr Blair's cabinet reshuffle on Wednesday.
Mr Howarth, an MP for Knows ley North, fills the vacancy left by Mr Paul Murphy, formerly the North's Minister for Political Development, who was promoted to Secretary of State for Wales in the reshuffle.
"I welcome George Howarth to the Northern Ireland team and look forward to working with him in the challenging months we have ahead of us," said Dr Mowlam.
According to sources at the NIO last night, Mr Howarth will stay a junior minister or parliamentary under-secretary of state at the NIO, joining Mr John McFall and Lord Dubs at that level.
It was described as a "sideways" move for Mr Howarth, although to a more dynamic and challenging department.
The exact portfolio to be taken up by Mr Howarth was not clear last night as some reshuffling of portfolios may take place over the next 24 hours. An announcement by the NIO is expected later today.
Mr Adam Ingram will remain at a senior ministerial level at the NIO, effectively acting as Dr Mowlam's number two. However, the speculation last night was that he would not automatically take over the entire political development portfolio as he may wish to retain his security and policing brief.
Mr Howarth (50) was first elected to the House of Commons in a by-election in November 1986. He suffers from a bad back; reports suggest he first injured it when he slipped a disc while sneezing during the 1986 campaign.
Ms Kate Hoey, the new sports minister replacing Mr Tony Banks, said yesterday that Mr Howarth would come to his Northern Ireland posting with "no hidden agenda, no baggage" and with an open mind. "He's very much a hands-on minister," she added.
In the past, Mr Howarth has been described as "competent if less than colourful", "unimpeachably worthy, formidably dull" and a "useful and articulate MP". He first joined the Labour Party in 1967 and was elected deputy leader of Knowsley Borough Council in 1982.
Housing and the environment have been issues high among his priorities as an MP. He was educated at Salford University, and is married with three children.