Nick Clegg tore into Boris Johnson’s decision to buy “lumbering second-hand” water cannon for use against rioters, saying they would fundamentally alter the way Britain is policed.
The Deputy Prime Minister opened a deep split in the Government, as Home Secretary Theresa May comes under pressure to authorise the use of the devices in the capital.
Mr Clegg said they would have been useless in the 2011 riots and would create an “embattled” sense of policing.
Former home secretary Jacqui Smith also criticised the Mayor, telling the Standard he had shown “a bloody cheek” for rushing ahead and saying the cannon would undermine “traditional public order policing”.
Ms Smith, who oversaw the policing of several major demonstrations when she was in charge at the Home Office, said police had told her they did not need or want such weapons.
Green campaigner Baroness Jenny Jones described water cannon as “dangerous” and said “the vast majority of Londoners” were against their use.
Critics also cited the case of German pensioner Dietrich Wagner, partially blinded when identical cannon were used against marchers in Stuttgart.
But City Hall sources insisted the ageing Wasserwerfer 9000 would arrive in London “within weeks” and said they were confident Mrs May would approve their use.
The three cannon will cost £218,000, which the Mayor regards as “a bargain” compared with new ones, but they are almost 20 years old.
Mr Clegg said the strong advice after the 2011 riots was that water cannon were only useful to keep back large crowds, not for fast-moving rioters.
“In the riots people were scurrying down small streets, smashing windows and then rushing off ... in a very fluid situation,” he said.
“The idea that great, lumbering second-hand German water cannon can somehow sort all that out is fanciful.”
He added: “It kind of rubs up against the long tradition of policing by consent. It creates a kind of embattled sense of how the police work.”
