Sir Bernard Hogan-Howe, centre, said: 'When the police and the security service and sometimes the military respond, we want to make sure that our ability ... is not restricted by things like live coverage.' Photograph: Jeff Overs/BBC/PA
Television news organisations are to be asked by Scotland Yard to consider not broadcasting live images of police or special forces preparing to storm any terrorist siege in London to avoid jeopardising the lives of hostages or armed forces trying to rescue them.
Sir Bernard Hogan-Howe, the Metropolitan police commissioner, said on Thursday he feared live coverage could hamper the ability of police or the military to respond.
Recent terrorist sieges in Paris and Sydney were accompanied by extensive live coverage on television. The fear is that hostage-takers may be tipped off about an impending rescue mission, with the authorities losing any element of surprise.
Metropolitan police officials held initial meetings with the UK's major broadcasters last week, specifically about broadcasting after the Paris attacks.
In previous terrorist incidents in the UK, police have had a voluntary agreement with broadcasters, under which they agreed not to show live pictures of police or special forces preparing to storm a site. In return they were permitted to keep filing for broadcast afterwards.
Hogan-Howe said: "We do have plans already but we have reviewed and refined them, in consequence of what we've discovered of the French experience, and also the way that we work with the press, as obviously what we all saw was live coverage of an ongoing event.
"That's something the public want to be informed about. Of course we as the police want them to be informed ... to make sure they are protected - but equally, when the police and the security service and sometimes the military respond, we want to make sure that our ability to respond is not restricted by things like live coverage. We have ongoing discussions with the media about how that happens."
Senior counter-terrorism officials in Britain fear an attack is a matter of when, not if.
One news executive said: "This is not something new but the events in Paris have concentrated minds."
Talks have been taking place between the police and broadcasters more frequently since the terror attacks in Mumbai in 2008, which were covered live on television, highlighting the problems facing broadcasters and the authorities.
Planners of the Mumbai attack, based in Pakistan, watched live TV coverage of the crisis and gave instructions via mobile phones to the terrorists who were holding hostages. Indian intelligence intercepted those calls and recorded them.
In a statement Scotland Yard said:"We have regular dialogue with news organisations and broadcasters about policing matters. These can cover a wide range of issues, including the security of police operations where a risk to life is involved.
"We're grateful to the media for listening to the challenges we face and for helping us understand their issues, such as safety and security, in fast-moving situations. Recent discussions have included terrorist incidents and their implications for police and the media."
Chris Webb, Scotland Yard's head of news in 2005 when London was hit by two terrorist attacks, said a voluntary agreement was hammered out with broadcasters.
When those behind the failed bomb attacks on 21 July 2005 were holed up days later and cornered in a west London flat, surrounded by armed officers, broadcasters were permitted to film but agreed not to transmit images live.
Webb said: "It is a difficult balancing act for the authorities. They have to look at how to protect life, especially if taking executive action [sending armed police or special forces in to end a siege].
"Images giving the bad guys prior warning can impact on the fate of the hostages inside, and get hostages or officers killed."
Webb warned that the massive growth of social media as well as the increase in the number of news channels makes avoiding coverage that tips off the terrorists much harder: "You can ask broadcasters to use discretion, you can't do the same with social media."
Senior news executives involved in the discussions say that while broadcasters are sensitive to the need to not put police operations at risk, there is also an imperative to safeguard editorial independence.
Any editorial curbs or restrictions the police might put forward will be considered, but not automatically adopted by broadcasters.
A spokesperson for Sky News said: "Last week Sky News attended a meeting with the Metropolitan police at their request. At that meeting we discussed reporting potential terrorist incidents in the wake of the Paris attacks."
An ITN spokesperson said: "We are in regular and ongoing discussions with the Met police around a wide range of issues, including the security concerns and challenges presented by the current heightened terrorist threat."