The Taser gun has been trialled in five police forces

The weapons could be used instead of the more lethal option of firearms.

Ministers have agreed to extend a pilot study which has taken place in five forces, on a strictly limited basis, since April 2003.

Independent Police Complaints Commission chair Nick Hardwick said it was "wise" to extend the scheme.

The electrical current can penetrate clothing up to two inches thick.

Under pressure

The weapons were proposed amid growing pressure to reduce the number of people shot dead by armed police.

The pilot study originally took place in Lincolnshire Police, Metropolitan Police Service, Northamptonshire Police, North Wales Police and Thames Valley Police.

Home Secretary David Blunkett said scientific evaluations had shown the Taser guns had a "very low" risk of fatality.

He said: "In the light of results of the trial, I have authorised chief officers throughout England and Wales to deploy Taser for use in the same strictly limited circumstances.

"Chief officers can now make the M26 Taser available to authorised firearms officers in their force as a less lethal alternative for use in situations where a firearms authority has been granted."

The US-based manufacturers of the device insist that it causes no long-term injuries and only short-term skin irritation.

'Less lethal' alternative

Welcoming the move, Mr Hardwick said: "The IPCC approves of the decision to widen use of the Taser as a less-lethal option to firearms.

"The year-long trial of the Taser and experience from police firearms incidents over many years show that it is wise to extend the Taser's use to all firearms units that seek it."

He went on to suggest that the use of the weapons is monitored to ensure that they are used safely.

Mr Hardwick added: "We will expect the police service to refer all incidents to us in which Tasers are discharged - we are conscious that Tasers could be misused and we will scrutinise any misuse.

"The key to their successful deployment lies in continuing to provide clear guidance and adequate training."

Since 1 April 2004 the IPCC has received 12 referrals of incidents in which Tasers were used by the Metropolitan Police Service, in addition to two referrals from Lincolnshire Police.

A Home Office spokesman said Taser weapons have been fired during 27 incidents in England and Wales since April 2003.

Scotland's chief constables are still considering adding the Taser stun gun to their armoury.