ARMED French sea marshals have been given the green light to patrol on Poole’s Barfleur ferry within British territorial waters, as part of an ongoing mission to deter terror attacks.

The UK government has agreed that armed French officers can operate on cross-Channel shipping on a port-to-port basis for the first time.

Previously, specially-trained personnel could only be airlifted onto ships while they were in international waters.

Now, armed officers will be able to travel in and out of UK ports, such as Poole, accompanying passengers for the entire duration of the crossing.

Brittany Ferries group commercial director Mike Bevans said: “We are delighted that this agreement has been reached.

“Point to point sea marshalling is a welcome step forward and will be a further reassurance to our passengers.”

Armed sea marshals were first deployed on the Barfleur in late August, this year, as the ferry sailed from Poole to Cherbourg.

On that occasion seven marshals were dropped by helicopter during the pre-scheduled operation, which took place in international waters more than 12 miles off the UK coast.

The marshals travelled with the ferry’s 369 passengers, patrolling public areas of the ship, then left on foot in Cherbourg.

Confirming the latest agreement, a Brittany Ferries spokesman said: “Personnel may now get on at one port and travel with the ship and its passengers for the duration of the journey, rather than having to be helicoptered onto and off the ship in international waters.”

The first sea marshal drop aboard a Brittany Ferries vessel took place earlier, this August, on a ship travelling from Portsmouth to Caen.

Armed French police started patrolling cross-Channel ferries this summer in response to the Paris terrorist attacks of November 2015, which claimed the lives of 130 people including 89 at the Bataclan theatre.

The armed patrols are part of the International Shipping and Port Security code, endorsed by the International Maritime Organisation.