The MET was today under pressure to reverse its decision to begin armed patrols on some London streets.

Members of the London Assembly demanded that Mayor Boris Johnson call an emergency meeting of the Metropolitan Police Authority, the capital's police watchdog.

They said the Met's decision, which will see machinegun-carrying officers engaged in routine policing for the first time, was "unacceptable" and harmful to community relations.

Others warned that the move — which is understood to have been announced without prior consultation with Mr Johnson — would increase, rather than allay, residents' fears.

The protests follow the disclosure yesterday that armed members of the Met's elite CO19 firearms squad are to begin routine patrols on "hotspot" streets and estates in Tottenham, Haringey and Brixton.

The decision follows a 17 per cent rise in gun crime in the capital over the past six months, fuelled by a Turkish gang war in north London and a rise in teenage gang shootings south of the river.

The Met, which has already begun the scheme, insists that the unprecedented tactic is a proportionate and temporary response to prevent armed gangs from controlling estates.

Labour's policing spokeswoman on the London Assembly, Joanne McCartney, said: "We want fewer guns on the streets, not more, and people to feel safe in their community — not scared of those who are supposed to protect them. There has been no debate and apparently no consideration of the strong opposition that exists to arming the police."

Jenny Jones, a Green member of the MPA, added: "This is a totally unacceptable departure from normal policing tactics. I hope the Met will rethink this terrible decision. I can't believe that the sight of a policeman with a machinegun will make people feel safer."

The anger has been inflamed because the move was disclosed in an article in the Police Review magazine, rather than through official channels.