The number of armed police officers in Bedfordshire, Hertfordshire and Cambridgeshire will be increased by 50 per cent to help protect the public from terrorism.

The joint firearms unit will be recruiting additional officers after they "reviewed capability and capacity in the light of current threat levels".

Many will be deployed in rapid-reaction teams, which will be on patrol and ready to react round the clock.

But the force stressed there was no specific terror threat in the county.

Temporary assistant Chief Constable Dan Vajzovic said: “Following national calls to train additional firearms officers across the country, the firearms capacity across the tri-force was reviewed.

“This review emphasised that we are strongly committed to the principle of having a largely unarmed police service that works with the consent of our communities.

“While our numbers of firearms officers were found to be adequate to meet our day-to-day demand, it was felt that it would be beneficial to increase the number of officers who are firearms trained by 50 per cent.

"This increase will ensure we have the capacity to deal with any foreseeable terrorist related event.

"These officers will not be deployed to deal with routine incidents but will be able to provide additional resilience in the event of the threat level increasing or in response to specific terrorist incidents.”

Last year, Prime Minister David Cameron set aside £143m over five years to boost the UK's armed response capability.

Police have said training for these roles has already started.