Police chief backs Met boss

Ken Jones, president of the Association of Chief Police Officers (Acpo) said Sir Ian's departure would be bad for policing in London. And he questioned whether it was appropriate to use health and safety law to prosecute the force over the shooting.

He told ITV's The Sunday Edition: "First and foremost I do not think this is the time for Sir Ian Blair to resign. It wasn't the commissioner on trial last week it was the organisation. If the public sector is to be characterised by failures and then people at the top going the public sector is never going to learn."

He went on: "I find it rather difficult (to understand) this cacophony of pressure on him to resign. It would not be good for policing.

Mr Jones said the 30-year-old law was designed for accidents on building sites and using it over Mr de Menezes's death raised "large questions".

"This legislation was designed for a different era, for a different purpose and fundamentally around factories and building sites. I think applying it 30 years later to this particularly extraordinary circumstance has introduced some very large questions which we need to answer."

Last week the force was found guilty at the Old Bailey of serious failings over the shooting. It fined £175,000 and ordered to pay £385,000 costs after being convicted by an Old Bailey jury of exposing the public to risk.

The trial heard there was a "catastrophic" series of 19 key failures in police procedure which led to Mr de Menezes being shot by armed officers on a train at Stockwell Tube station on July 22 2005.

Shadow Home Secretary David Davis repeated calls for Sir Ian to resign but admitted putting the Met on trial for health and safety offences was "frankly bonkers".

He insisted he did not believe in "hounding people out of office" but believed the Commissioner had to be "held responsible" for the failures of July 22 2005.