JEREMY CORBYN has come under pressure to say whether he would be prepared to use Britain’s Trident nuclear deterrent if he becomes prime minister.

The Labour leader, a lifelong opponent of nuclear weapons, has in the past said he would not authorise a nuclear strike — even though the party is committed to retaining Trident.

But shadow foreign secretary Emily Thornberry refused to say yesterday whether there were any circumstances in which Mr Corbyn could order its use.

‘The use of a nuclear weapon is a decision [for a politician] that is completely out on its own,’ she told ITV’s Good Morning Britain.

‘No one in the end knows how they would use it, whether they would use it, because it has such extraordinary force and millions of people can be killed.’

Until recently, political leaders, including Margaret Thatcher, had avoided saying whether they would actually use the deterrent, Ms Thornberry said. ‘I’m of the view that it’s best for us not to say one way or the other, just as we have done for generations.’

Pressed on what Mr Corbyn would do if an enemy had carried out a nuclear strike on the north of England and was planning another on London, she said: ‘Who knows? That’s kind of the point.’

Defence minister Johnny Mercer said: ‘If Jeremy Corbyn is unable to make crucial decisions to keep our country safe, he is not fit to be prime minister.

‘It is important that Labour urgently clarifies their position on whether or not they would actually be prepared to use our nuclear deterrent if needed.’

Admiral Lord West, former head of the Royal Navy who served as security minister in Gordon Brown’s Labour government, told Sky News: ‘When someone says “I’ll never press the button” he doesn’t understand deterrence. That worries me.’

■ LABOUR has pledged a qualified counsellor at every secondary school in England to help young people live happier, heathier lives. It plans to recruit 3,500, and would ensure primary schools had a visit from a counsellor at least once a week, as it announced an extra £845million a year for its Healthy Young Minds plan. One in eight five- to 19-year-olds had a mental health disorder in 2017, figures show. Labour leader Jeremy Corbyn said: ‘Our society is fuelling mental illness on a huge scale and our young people are not getting the support they need.’

■ AT LEAST £1billion of North Sea revenues should be used to help areas dependent on the oil and gas sector switch to a greener economy, says Nicola Sturgeon. The Scottish First Minister and SNP leader wants to see areas such as Aberdeen and the north-east of Scotland ‘supported to make the transition to new low- or no-carbon industries’. Her party is calling for the entire £8.5billion revenue forecast for the oil and gas sectors over the next five years to be ring-fenced and used to tackle the climate crisis.