Neil Kinnock has warned his party not to ignore the nationalist threat posed by Nigel Farage, as concern grows in Labour ranks that Reform UK could pose a long-term threat for them as well as for the Conservatives. The former Labour leader told the Guardian he wanted Labour to turn its guns on Farage’s party in the final week of the election campaign, saying the populist right could gain a stronghold in the UK as it has across much of Europe. Labour has been accused of not putting up a fight against Farage because the Reform party appeared to be taking more votes from the Conservatives. But with Reform predicted by some pollsters to win more than a dozen parliamentary seats next week, Kinnock said Labour needed to start taking the threat seriously. “There is no next time. It [targeting Reform] must start now,” he said. “We have to combat this populist nationalism with words, in explaining to people what these people are, not just who they are. “People like Farage love the personal attention like all narcissists, so we have to focus on explaining what they are and all their inconsistencies and falsehoods. They plant and harvest lies – they always have.” Kinnock added that if Labour was overly cautious in government, it would play into Reform’s narrative that there was little difference between the two main parties. “Absolutely vitally, [the populist right] have to be combated with actions,” he said. “That means the implementation of change which is positive and cumulative, and driven by strong purpose in the service of the community.” Farage and his party were recently criticised over an undercover recording that showed two of his party activists using offensive language while out campaigning for him in Clacton in Essex. The row has threatened to overshadow what has otherwise been a strong campaign for Reform in which it has risen from about 11% in the polls to 16%. Kinnock compared Farage’s response to the controversy in Clacton – inserting ambiguity and going on the attack – to that of Donald Trump. “It’s straight out of Trump Towers. It’s Farage the thespian. He’s doubling down on his claims that Channel 4 had hired an actor,” he said. “It’s what the nationalist populists do time and time again. They mislead people and you can add Boris Johnson to that as well.” Labour was this week accused of failing to fight against Farage in Clacton after the party’s candidate was instructed to leave the constituency over a belief that he was “distracting” from Keir Starmer’s campaign. The local Labour campaign in Clacton said it had been banned from printing leaflets, blocked from using campaigning software, and had its access to the campaign’s social media overridden – its posts on X were deleted. Asked this week if activists were allowed to campaign in Clacton, Starmer said: “The chief of operations tells people where we most want them to go and fight, but we have got to fight in Clacton – of course we have.” He criticised Farage on Friday for creating an atmosphere in which racist comments were tolerated, saying it was a “test of leadership” for Farage. Many candidates and polling experts believe Reform is likely to perform better than expected next week and could gain more than a dozen seats. An MRP poll by Electoral Calculus and Find Out Now this week showed Reform heading for 18 seats, with Farage, the former party leader Richard Tice and the former Tory MP Lee Anderson all predicted to win. Labour candidates in some target seats say they are also becoming nervous that many of the undecided voters they were hoping would vote for them are being attracted by Reform instead. “There are still a few more undecided voters than we might like, so we’re getting more nervous the closer we get,” said one. “We’re meeting a lot of people who are not Tory, but deciding between Labour and Reform.” A Labour official said the new party was eating into its votes in key target seats such as Great Yarmouth and Ashfield. “It’s only now that the serious threat of Reform is something that we’re looking at,” they said. “That only becomes a problem if things are closer than the polls suggest it’s going to be.” Rob Ford, a professor of political science at Manchester University, said Labour needed to be alert to the appeal that Reform had among voters in “red wall” constituencies in particular. “In the longer run, that is going to be an issue for Labour,” he said. “The party is likely to find itself caught between members and activists who are left/liberal and the kinds of voters it has won at this election, many of whom are much less so.” Kinnock warned his party that leaving the Conservatives to combat Farage’s threat would backfire. “I hope that [the Tories] will resist Faragism, but they haven’t shown guts for the fight, and they’re going to have to,” he said. Labour officials say they are alive to the risk that Reform poses and say they plan to confront Farage and his politics “from day one” if they make it into power. “If Labour wins the election, we would want to make sure we stop Farage in his tracks,” one insider said. “We need to meet voters where they are, we need to tell them how we’ll address their concerns, and then show them that we’ll do it.”