Britain's biggest police force is set to reveal a boost in the number of firearms officers in the wake of terrorist atrocities involving marauding gunmen.
Scotland Yard is preparing to make an announcement on Thursday including the scale of the planned increase, which was mooted following the recent attacks by fanatics in Paris which saw 130 people killed.
In a radio interview on Wednesday morning Metropolitan Police Commissioner Sir Bernard Hogan-Howe said a "significant" announcement will be made in the next 24 hours.
He told Nick Ferrari on LBC: "We are determined to increase the number of firearms officers. In fact I believe over the next 24 hours I'll be able to make a significant announcement about that."
There are currently around 2,000 firearms officers in the Metropolitan Police and the number of armed patrols was increased after the murders in France.
Last month UK counter-terrorism bosses revealed for the first time that police marksmen are being told to walk over casualties and go forward to confront terrorist gunmen should there be an attack.
Assistant Commissioner Patricia Gallan said then that there was likely to be an increase in the number of trained firearms officers in the capital.
Outgoing City of London Police Commissioner Adrian Leppard also suggested that the Army could be called in to man armed cordons if there were multiple gun and bomb attacks, as in the French capital.
Sir Bernard revealed he is meeting with armed officers every two weeks in a bid to maintain morale, after he raised concerns that marksmen should have greater protection in the wake of a fatal shooting.
This followed the death of Jermaine Baker, 28, during a police operation to stop an alleged prison break in north London in December.
He said: "I've actually met a very large number of our firearms officers after the incident in Haringey to see how they felt, what their complaints might be and I've got a taskforce running now.
"I'm seeing a group of them every two weeks with things that I've put in place to encourage more officers to feel that they've got confidence that I'm supporting them, and in turn the public are supporting them."
Prime Minister David Cameron is considering legal changes to make it more difficult to prosecute police marksmen who shoot terrorists.