The 50,000 volt charge from the gun temporarily disables the target

The Metropolitan Police Authority (MPA) refused to accept the proposals after they found the stun guns were meant to be used "in addition to firearms".

The force currently uses 280 Taser guns, which uses a 50,000-volt charge to incapacitate those it is used on.

Officers used the electric stun guns in 47 incidents between January and August this year.

Ten forces across England and Wales are taking part in trials extending their use.

'Less lethal option'

The MPA report shows a small increase in the use of Taser guns, which were used in 45 incidents between January and August 2006.

This year they were used when officers were confronted by suspected armed robbers, wanted murderers and other violent people.

Cindy Butts, MPA deputy chair, said: "The authority previously agreed to the deployment of Tasers in London as an alternative to firearms, and undoubtedly their deployment to critical incidents have saved lives.

"However, the proposal brought to us today was for Tasers to be used in addition to firearms, which is a significant development and one we were not happy to agree to without greater explanation of the implications and justification for this move," she said.

Temporarily disabled

When Tasers are fired, two metal barbs connected to the weapon by a thin wire pierce the skin before the charge is delivered.

Amnesty International said the weapons, which temporarily disable a suspect, have been linked to more than 70 deaths in America.

The youngest person targeted by police using Taser guns was 16, while the oldest was 43, the report to the MPA's Co-ordination and Policing Committee stated.