Labour’s commitment to maintaining the UK’s nuclear weapons is “non-negotiable”, the party’s shadow defence minister, John Healey, is expected to say in a speech on Friday, emphasising a deliberate shift in tone from the Jeremy Corbyn era. In a speech that implicitly acknowledges the perception by some within Labour that Corbyn’s public doubts over nuclear weapons and Nato helped damage the party’s reputation with certain voters, Healey will also stress the party’s commitment to the North Atlantic alliance, and to maintaining a viable UK defence industry. While Labour’s 2017 and 2019 manifestos both pledged to support the renewal of the UK’s Trident nuclear submarine system, and to back multilateral rather than unilateral nuclear disarmament efforts, these were very obviously compromises accepted by Corbyn. Corbyn is a longtime and active supporter of the Campaign for Nuclear Disarmament, and spoke at an anti-Trident demonstration in 2016, when he was Labour leader. He has also expressed scepticism about Nato, and during a debate in 2016 declined to confirm that he would abide by a key element of membership and commit to the defence of a fellow Nato member that had been attacked by an outside country. Speaking at the Royal United Service Institute thinktank on Friday, Healey will link the UK’s Nato membership to a wider commitment to international treaties. “First, Labour’s commitment to Nato is unshakeable,” he is due to say, according to extracts of the speech released in advance. “Second, Labour’s support for the UK’s nuclear deterrent is non-negotiable. Third, Labour’s commitment to international law and the UN, to universal human rights and to the multilateral treaties and organisations that uphold them, is total. “And fourth, Labour’s determination to see British investment directed first to British industry is fundamental, not just to our thinking on defence, but on the kind of society we want to build.” Labour is, Healey will argue, “the party of sovereign defence capability – we see the steel industry, the shipyards, the aerospace and materials industries as a national asset. “We want to see a clear plan from government to enhance these capabilities. We want to see, for the good of our country, as much as possible of our equipment designed and built here.” The reaffirmation over nuclear weapons in particular appears set to reignite arguments that have raged within Labour for decades between those who support the idea and others, Corbyn prominent among them, who have long argued that the UK should unilaterally abandon weapons that no rational prime minister could ever use. On defence more widely, Healey is expected to accuse the government of having a lack of coherence, “fudging and fumbling our way into the future, with major procurement projects at the mercy of the illusion that ‘something will turn up’ to pay for them”. The government is due to publish the so-called integrated review, covering priorities in the coming years for defence, security and foreign policy. In his planned speech, Healey said this should address long-term funding shortfalls, calling this “the Achilles heel of defence plans”.