Boris Johnson joins fight to free Chennai Six

The move by the fUK foreign secretaty follows action by East Ren MP Paul Masterton, who recently met Rory Stewart MP, Minister of State at the Foreign and Commonwealth Office.

He had vowed to bring fresh impetus to bear on a case which has dragged on for four years.

Mr Irving, one of the so-called Chennai Six, was jailed for five years after the pirate-hunting vessel on which he was serving as an armed guard entered Indian territorial waters.

The judiciary of the state of Chennai jailed him on specious arms charges,and five colleagues, even although they had previously been released by the Indian national judiciary.

A high profile campaign featuring politicians and celebrities, besides many other supporters among the general public, has so far failed to win the men’s release.

Mr Irving’s partner Yvonne McHugh (pictured in group) has waged an unremitting campaign for Mr Irving’s release, and having visited the Chennai prison has spoken freely of the grim conditions the prisoners have to endure.

The six ex-paratroopers were working for Advanfort, a US maritime security company, to protect ships in international waters when they were arrested in October 2013 for disputed firearms offences.

Mr Masterton said: “This was an issue that my predecessor (Kirsten Oswald MP) first raised with the Foreign and Commonwealth Office and I intend to breath new life into it to ensure as much pressure as possible is brought to bear to secure the release of Billy Irving.

“Mr Irving’s fiancée and young son are my constituents and they will receive my full support.

“I cannot imagine the stress and worry that this must be causing for them.

“Hopefully alongside other Members of Parliament whose constituents are detained with Mr Irving we can work with Ministers to exert substantial pressure for their release.”