There have been calls for the Home secretary Theresa May to deploy water cannons as police struggled to control rampaging mobs during a second night of riots across London.

Patrick Mercer said that police be allowed to use high pressure hoses regularly used to quell riots in Northern Ireland.

 “I find it strange that we are willing to use these sort of measures against the Irish yet when Englishmen step out of line and behave in this atrocious and appalling way, we are happy to mollycoddle them,” he said. “If the police want cannon then they should be allowed to use them. I have used water cannon myself and I found them extremely effective.”

Former London mayor Ken Livingstone also supports the police’s use of water canons to control rioters. “The issue of water cannon would be very useful given the level of arson we are seeing here,”  he said.

The Home Secretary faced calls to use water canons as a response to the violent student protests last year but decided against it telling MPs: “I don’t think anybody wants to see water cannon used on the streets of Britain because we have a different attitude to the culture of policing here. We police by consent and it depends on that trust between the police and the public.”

The Home Office have ruled out the use of water cannons.

“Water cannon are not approved for use on the mainland by the Home Office,” a spokesman said. “A range of measures is available to the police to tackle disorder and we do not believe water cannon are needed.”

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