Tory Mayor of London Boris Johnson is trying to force through controversial plans to unleash water cannon on London's citizens despite widespread opposition.

Twenty of 25 London Assembly members recently voted against the riot-control plans and a poll by the Met Police showed that out of 2,547 people asked about water cannon engagement only 59 were in favour.

But in an attempt to side-step the opposition, Mr Johnson said he would write to Home Secretary Theresa May, who has the final say on their deployment, for permission to go ahead.

The mayor plans to buy three retired German water cannon within weeks, at a cost of up to £300,000.

Labour's London Assembly police and crime spokeswoman Joanne McCartney said: "I'm deeply concerned that the Mayor is rushing the purchase of water cannon without a proper public debate.

"It is disgraceful that the Mayor has not even read the London Assembly police and crime committee report on water cannon.

"It clearly stated there was contradictory evidence on their effectiveness and that the case had not been made."

Ms McCartney pointed out that the money would be better spent on more frontline police.

"Water cannon are no substitute for a visible uniformed presence on our streets," she added.

"The Mayor is trying to bounce this decision through in a matter of weeks and Londoners are being given virtually no chance to express their views."