The current chairman of the Government's Joint Intelligence Committee, John Scarlett, is to be the new chief of the Secret Intelligence Service MI6.
Downing Street's announcement immediately sparked political dismay among the Conservatives and Liberal Democrats, because it comes before the report of the Government-appointed Butler Inquiry over intelligence in the run-up to the Iraq war.
Mr Scarlett succeeds Sir Richard Dearlove who is becoming Master at Pembroke College, Cambridge, and will take up his appointment this summer.
Mr Scarlett became the first head of the JIC to become widely known when he gave evidence to the Hutton Inquiry into the death of weapons expert Dr David Kelly.
The Foreign Secretary Jack Straw made the appointment on the basis of a recommendation of a selection panel chaired by Downing Street's security and intelligence co-ordinator Sir David Omand.
Mr Straw said: "The Secret Intelligence Service is in the front line of our defence against terrorism, weapons of mass destruction and other threats.
"The role of the chief of the service is a vital one and a very demanding one. John Scarlett has the operational background, personal qualities and wide experience to be a worthy successor to Richard Dearlove.
"Under Richard's leadership, SIS has worked tirelessly to support the UK's vital interests in the fields of security, defence, foreign and economic policies and I take this opportunity to pay tribute to this work, necessarily out of the public eye, which the members of SIS undertake on all our behalves."
The appointment of Mr Scarlett was condemned as "inapproriate" by the shadow foreign secretary Michael Ancram.
"In today's world Britain's Secret Intelligence Service is central to our national security. And it is essential the whole country has the fullest confidence in it," he said.
"The Government-appointed Butler Inquiry is currently reviewing the whole question of intelligence, and the use made of it, in the run-up to the Iraq War. Given that John Scarlett is central to that review, and that the inquiry has not yet reported, I believe that this appointment, at this time, is inappropriate."
The Liberal Democrat foreign affairs spokesman Sir Menzies Campbell also questioned the appointment.
"In view of the evidence at the Hutton Inquiry, this appointment can only be described as highly controversial," he said. "It will only be justified if Mr Scarlett proves to be an effective head of MI6 at a time when success in the campaign against terrorism is essential.
"The responsibility for ensuring that he is not embroiled in political controversy rests fairly and squarely with ministers."
The Prime Minister's official spokesman insisted: "This appointment has been made on merit, on the basis of one recommendation from the selection panel."
The spokesman said today's appointment had been made in exactly the same way as that of Sir Richard and his predecessor.
Mr Scarlett has spent his whole career in MI6, after leaving Magdalen College, Oxford in 1970 where he took a First in Modern History.
He has had a number of operational postings at home and abroad and is a previous SIS Head of Station in Moscow.
Mr Scarlett became chairman of the JIC in September 2001 and is also currently head of the Intelligence and Security Secretariat in the Cabinet Office with overall responsibility for its security policy division.
He speaks Russian and French and is married with three daughters and one son.
Downing Street said Mr Scarlett would follow SIS practice in not giving interviews, making public appearances or providing on-the-record comment.
When Sir Richard gave evidence to the Hutton Inquiry he did so in audio only and his face was never seen.Reuse content