Healey – who quit earlier this month after accusing the prime minister of being ‘unwilling to commit the resources’ needed to keep Britain safe – urged the government to set out a target date for the UK to spend 3 per cent of GDP on defence

The new defence investment plan has allocated £14.5bn to fund Britain’s defence, still falling well short of the £28bn officials previously said was needed

John Healey, who quit the Cabinet earlier this month after bitter wrangling with the Treasury, insisted the £15billion package would not keep the country safe from rising threats.