Britain has not fought a just conflict since the Second World War, Jeremy Corbyn has said, insisting he would only authorise military action as a "genuine last resort".

Mr Corbyn refused to commit to sending British troops to defend a Nato ally which was under attack, saying he would seek economic and diplomatic solutions to any crisis.

Mr Corbyn, who is a member of the Campaign for Nuclear Disarmament, raised questions about the future of the Trident nuclear deterrent, saying it would be included in a defence review if Labour wins the election.

A Labour MP pointed to how Mr Corbyn had supported the IRA when it was bombing mainland Britain in the 1980s, saying: "He's just anti-western military interventions."

The Labour leader’s comments were also attacked by Rob Gray, an Army veteran who was jeered for challenging Mr Corbyn over his views on prosecuting veterans in Northern Ireland this week.

Mr Gray said: “The man’s an idiot. Jeremy Corbyn is an insult to friends of mine who died in Northern Ireland because he will not support British troops.

“The man does not care about our war dead, he cares more about the IRA dead, Hezbollah dead.”