Water cannon could be used on the streets of mainland Britain for the first time under plans being examined by police chiefs.
Forces have been looking at the way the RUC in Northern Ireland has used water cannon and armoured vehicles after a series of violent demonstrations and rioting in British cities in which a large number of officers have been injured.
The use of water cannon, recently seen in action against anti-capitalist demonstrators in Genoa, is being examined as a "priority" by a police and Home Office working party as a "less than lethal" option to firearms.
Tim Hollis, Assistant Chief Constable of South Yorkshire and a spokesman on public order issues for the Association of Chief Police Officers, said the possibility of using water cannon, which was considered and rejected 15 years ago, had been heightened by recent rioting in Bradford, Oldham and Burnley.
The introduction of the cannon, which blast jets of water at high pressure, would outrage civil rights groups and would be controversial at a time when the Italian police have been accused of over-reacting and using excessive violence.
Police have also been considering the use of baton rounds (plastic-coated bullets), firearms that fire tranquillisers, and electric stun guns, although after the Bradford riots David Blunkett, the Home Secretary, ruled out the use of water cannon and rubber bullets to restore order to the streets.
Mr Hollis told Police Review magazine: "The working group looking at 'less than lethal' options has got water cannons on the priority list and the Police Scientific Development Branch will be looking at the effectiveness and safety factors in the near future. Additionally two forces have been looking at the [water cannon] vehicles in Northern Ireland to inform their decisions."
He argued that cannon "have been used in Northern Ireland during the marching season for the past two years, so actual operational experience is available to the review team".
He added: "We certainly need to look at them again. Let's remember that some forces explored their use some 15 years ago, but didn't go ahead and use them.
"However, the technology has moved on since then and we do need something to help us regain ground quickly and safely and to relieve the pressure on officers holding static lines."
He warned: "Water cannons could not, however, be brought in overnight. You need specialist training and tactics to use them safely.
"The level of violent disorder that was witnessed in Bradford raised, once again, the question of whether the police have sufficient equipment to protect both the public and its officers."