Taser guns have previously only been available to police officers with firearms training.

But today use of the guns is rolled out to ten police forces, including the Metropolitan Police.

The 50,000 volt guns release an electric charge to temporarily paralyse a target.

A spokesman for the Home Office said: "Taser guns give the police an additional tactical option. The officers using the Tasers are specially trained."

But the move has been criticised by human rights group Amnesty International (AI).

A spokesman for AI said: "These are potentially very dangerous weapons. Firearms officers undergo continuous training. I understand they undergo training for real life situations.

"And they undergo repeated training every month to keep them up to date. What we don't know is exactly what the nature of the training is that non-firearms officers will receive.

"And we're concerned that it won't be up to the same standard."

Tony McNulty, The Minister for Security, Counter-Terrorism, Crime and Policing, said: "I approve a 12 month trial of the deployment of Taser by specially trained units who are not firearms officers in similarly violent circumstances requiring conflict management. "All Taser deployments will continue to be monitored and a detailed report of every deployment will be produced. These reports will be collated by the Home Office Scientific Development Branch and summarised on a three-monthly basis for assessment."