Blunkett and Straw thwart Blair's plans to reduce their empires in cabinet reshuffle

David Blunkett and Jack Straw have fought off proposals by Downing Street to trim their Whitehall empires when Tony Blair makes a cabinet reshuffle today. The Prime Minister's plans to freshen his team provoked two "turf wars" as Mr Blunkett and Mr Straw resisted moves that would have reduced their influence.

Lord Irvine of Lairg, 62, the Lord Chancellor, is expected to retire in the reshuffle. Ministers likely to move include Geoff Hoon, the Defence Secretary and Lord Falconer of Thoroton, the Home Office minister and Mr Blair's former flatmate, tipped for the Cabinet.

Mr Straw, the Foreign Secretary, has blocked a plan by No 10 to upgrade the middle-ranking post of minister for Europe to cabinet level as a sign of Mr Blair's commitment to the EU. Peter Hain, the Secretary of State for Wales, who represents the Government on the Convention on the Future of Europe, was earmarked, but Mr Straw opposed having two Foreign Office ministers in the Cabinet. Mr Blunkett, the Home Secretary, is believed to have thwarted a plan to turn the Home Office into a Ministry of the Interior, responsible for terrorism, asylum, police and crime.

Many of the responsibilities of the Lord Chancellor's Department are likely to be transferred to a new Ministry of Justice, which could be headed by Mr Hoon. Under Downing Street's original plan, prisons and probation would have switched from the Home Office to the new justice ministry, but Mr Blunkett's department will survive largely intact. Yesterday, as he presented wide-ranging plans to overhaul of the criminal justice system, Mr Blunkett came close to declaring victory.

He told BBC Radio 4: "I think where we can join up the work of the police, that is, from arrest all the way through to rehabilitation, it makes more sense than to fragment the system. I think the Prime Minister agrees with that." A Whitehall insider said: "What seems to have happened is David Blunkett has fought off the prospect of losing great chunks of criminal justice."

The posts of Scottish and Welsh secretary are expected to be merged and Mr Hain may take on the expanded brief. Mr Blair is considering a new cabinet post of Minister for Children and Paul Boateng, the Chief Treasury Secretary, has been tipped for the job.

The Cabinet's most senior ministers, John Prescott, Gordon Brown, Mr Straw and Mr Blunkett, will stay in their posts. Patricia Hewitt, the Trade and Industry Secretary, may be moved. Alan Milburn, the Secretary of State for Health, and Charles Clarke, the Secretary of State for Education, are also expected to remain in their jobs.