Menezes police were not given shoot-to-kill order

The jury also heard that Met commanders twice changed their minds during the moments leading up to the fatal shooting at Stockwell Tube station.

At first, the plan was to let surveillance officers detain him before he entered the Tube - a move that would have saved his life.

That decision was changed seconds later, however, when Cressida Dick, the Met Commander in charge of the operation, ruled that armed officers from Scotland Yard's SO19 firearms team should carry out the arrest.

It also emerged that officers tracking Mr de Menezes changed their minds about whether he was the terror suspect they were seeking - 21/7 bomber Hussain Osman.

The dramatic revelations came on the fourth day of the Old Bailey trial in which the Met is being prosecuted under health and safety laws for its allegedly "catastrophic" failure to properly protect the public during the 22 July 2005 operation.

Mr de Menezes, 27, had been followed by police to the Tube from a block of flats in Scotia Road, Tulse Hill, which was under surveillance for being linked to Osman. Today the Met's senior counter-terrorism officer, Det Supt Jon Boutcher, gave more details of the confusion at the top of the Met's chain of command in the hours leading up to the shooting.

He claimed that the reason for the four-hour delay in firearms officers getting to Stockwell was because of doubts about Mr de Menezes's identity.

This also resulted in the "shoot to kill" order never being given.

Barrister Ronnie Thwaites QC, representing the Met, asked: "At no stage was the command given?" Mr Boutcher replied: "That is absolutely correct." Prosecutor Clare Montgomery QC asked: "Was the intervention on a carriage in a Tube train a good or bad place to carry out an intervention?"

The officer replied: "It was the first available opportunity. It is not ideal but in London there are very few places for an ideal intervention to occur."

Mr Boutcher said he thought it was "reasonable" that the firearms team only came on duty at 7am even though the operation began at 5am. "If somebody had come out at 6am there would have to be an emergency deployment," he said. The trial continues.