A ban on smoking for future generations moved a step closer last night, but Rishi Sunak suffered a blow to his authority after dozens of Conservative MPs voted against it. The House of Commons voted by 383 to 67 in favour of the prime minister’s plan to make it illegal for anyone born in 2009 or later to buy tobacco products in the UK. The legislation, which would effectively ban smoking for future generations by raising the legal age every year, is seen by the prime minister’s allies as a key part of his political legacy. However the result, voted against by 57 Tory MPs – including Kemi Badenoch, a likely future leadership contender, and five other ministers – underlined the depth of division within the party even over Sunak’s flagship policies. Labour has thrown its weight behind the plan, which was unveiled at the Tory party conference in October, ensuring that it sailed through the Commons. More than 100 Tory MPs abstained, although some of them will have been absent from the Commons for reasons unrelated to the vote. Badenoch, the business secretary, was the only cabinet minister to vote against the legislation. She said before the vote that she had “significant concerns” because the legislation meant that “people born a day apart will have permanently different rights”. She told LBC after the vote: “I don’t think the end justifies the means. The principle I was against was treating adults differently and how that would be enforced. It didn’t feel right to me.” Five other ministers – Julia Lopez, Alex Burghart, Steve Baker, Lee Rowley and Andrew Griffith – also voted against it. Penny Mordaunt, the Commons leader, was among dozens of Tory MPs who abstained. Conservative MPs were given a free vote although Andrea Leadsom, the junior health minister in charge of the bill, contacted some of them to make the government’s case. Opposition to the plans was led by the former prime minister Liz Truss, who told the Commons she was “very concerned” it was “emblematic of a technocratic establishment in this country that wants to limit people’s freedom”. Tory critics said the proposal would result in adults being treated differently according to their age, and it was a slippery slope that could lead to bans on fast food or alcohol. Some MPs argued the plan would encourage an illegal tobacco trade and that it would be difficult to enforce. Among those who voted against the ban were Truss, the former business secretary Simon Clarke, the former home secretary Suella Braverman, and the former immigration minister Robert Jenrick. Several Tory MPs with links to the vaping industry spoke in opposition to the bill. Mark Eastwood, the vice-chair of the all-party parliamentary group for responsible vaping, argued it would push people from vaping to smoking. Adam Afriyie, who received an award last year from a vaping industry group, said he could not support the proposal because it would treat adults differently according to their age. The legislation would not ban vaping but it would introduce greater restrictions, especially on marketing vapes at young people. The plan for a smoking ban is modelled on proposals in New Zealand, which were repealed earlier this year, before they took effect, by a new rightwing government in Wellington. Senior Tories including Sajid Javid, the former health secretary, and Steve Brine, the chair of the health select committee, spoke in favour of the legislation and said it would relieve pressure on the NHS and free future generations from smoking addictions. Polling by Savanta published on Tuesday suggested that 64% of Conservative voters were in favour of the plan. “Can we honestly say that this drug enhances personal liberty and freedom? It’s a nonsense argument – anyone who makes that argument, they’re choosing to stand up for big tobacco against the interests of their constituents,” Javid told MPs. The Guardian revealed this week that tobacco firms were lobbying politicians to oppose the legislation and instead support raising the smoking age from 18 to 21 in an attempt to avoid an outright ban. “Given what we know it is of course right to protect future generations from this drug and this addiction. The freedom from pain, from disease and inequality, is one of the greatest freedoms that there is,” Javid said. Victoria Atkins, the health secretary, told the Commons before the vote that there was “no liberty in addiction”. “Nicotine robs people of their freedom to choose,” she said. “The vast majority of smokers start when they are young, and three-quarters say that if they could turn back the clock they would not have started.” Labour used Tory opponents’ arguments to mock the government, and pointed to former Tory ministers’ links to tobacco companies. Wes Streeting, the shadow health secretary, told the Commons: “Of all the policies the Conservatives have adopted from the Labour party in the past few years, nothing shows our dominance in the battle of ideas more than this latest capitulation. “We happily align ourselves with big health in defence of the nation and we are only too happy to defend the health secretary against the siren voices of big tobacco we see gathered around our former prime minister in the corner of the chamber. “A stopped clock is right twice a day, and I find myself agreeing with the former prime minister. This is absolutely an un-Conservative bill, it is a Labour bill, and we are delighted to see the government bring it forward.” After the vote Deborah Arnott, the chief executive of Action on Smoking and Health, said: “Parliament has today begun the process of consigning smoking to the ‘ash heap’ of history. “However, this is only the first step, the bill must now go through committee and another vote before going through the same process in the House of Lords. The passage of the bill should be expedited to ensure it is on the statute book before the general election.”