Downing Street has denied that Royal Marines' commander Brigadier Roger Lane is to be replaced because of his performance.

His successor, Brigadier Jim Dutton, will take control of the Afghan mission at the end of June.

He is currently serving as liaison officer to the US central command in Florida.

Number 10 said the change was made for administrative reasons by the MoD and first announced last February.

A spokesman denied the decision was made because of Lane's controversial performance in Afghanistan.

The comments came after defence secretary Geoff Hoon said he retained "complete confidence" in the Royal Marines' commander, despite indications he faced pressure to sack the officer.

"I have every confidence in Brigadier Lane. He is doing a tremendous job in very difficult conditions and he deserves - and gets - our complete support," Hoon said.

The Sunday Telegraph had earlier quoted one Ministry of Defence official as saying that Marines commander Brigadier Roger Lane had mishandled relations with America and had lost the confidence of his troops.

"Brig Lane is a man out of his depth and should be sacked. The whole operation is quickly becoming a farce," said the unnamed official.

"[He] has lost the confidence of his men, his junior commanders and his tactical decisions look increasingly like the actions of a man desperate for some success."

But Downing Street denied the story was true. "Factually, this story has been wrong from beginning to end," said the Number 10 spokesman.

"The government, the secretary of state and the prime minister all believe that Brigadier Lane has done an outstanding job."

Shadow defence secretary Bernard Jenkin said the row over Lane's position had undermined the Afghan mission.

"It's a shame that the government's spin has got so far ahead of the operation in some cases that it has undermined the whole credibility of the operation and ultimately this has a damaging effect on the morale of the troops on the ground," he told the BBC Radio 4 Today programme.

Bruce George, the chairman of the defence select committee and Labour MP for Walsall South, also condemned the decision.

"It is deplorable if this man, who has had a very successful military career, who is doing an immensely difficult job in circumstances that are almost impossible to believe and then he leaves his post under a cloud," he said.

"I think that anybody who tries to stick the knife into him I think deserves to be criticised themselves."

Speaking on BBC1's Breakfast with Frost programme on Sunday, Hoon was also forced to defend the role of British combat troops in Afghanistan, calling operations there a "remarkable success".

He also said that despite the lack of contact with enemy forces it was important to deny territory to the terrorists.

"It is right that we should use whatever force is appropriate to make sure that they can't provide a threat to both the people of Afghanistan and to the wider world."

He said the work of British troops had not been over-hyped.

"I believe that we are setting out very clearly what has happened," Hoon told the BBC.

His comments followed repeated questioning of the Marines' mission, with Labour MP Doug Henderson the latest to join the growing chorus of critics.

He said there was a "suspicion" that the mission had been hyped up because "probably not a lot has been achieved".

Former Conservative armed forces minister Nicholas Soames also said the government had hyped the operations "as if they were about to embark on D-Day".

The mission had previously come under fire for its failure to find any al Qaeda or Taliban troops, and there have been reports that ammunition destroyed by UK forces belonged to a warlord loyal to the interim administration,

Operations were also hit by the quarantining of soldiers following a suspected outbreak of the winter vomiting bug.