Rishi Sunak’s change of government targets on immigration has prompted discontent among restless Conservative backbenchers, with some seeking a meeting with the home secretary, Suella Braverman. It comes after the prime minister set a new goal of bringing migration down below the level he “inherited”, which was about 500,000 net arrivals a year when he took office. Sunak redefined his target on immigration while in Japan for the G7 meeting after earlier in the week backing away from the Tories’ 2019 manifesto promise to reduce it below the level then of about 220,000. Adam Holloway, the Conservative MP for Gravesham in Kent, said the party’s electoral prospects were “shattered” by the migration figures of recent years and said he would seek a meeting with Braverman. Asked by the former Brexit party leader Nigel Farage on GB News why backbench MPs were not raising their voices, Holloway replied: “I would go further, it’s completely insane. Who would think that a Conservative government was presiding over effectively uncontrolled immigration? “I know that at least a group of us are asking to see the home secretary next week, because it’s not just about the Tory party’s electoral prospects that are shattered by this,” he told Farage. Another MP told the Guardian they expected it to be raised at next week’s meeting of the 1922 Committee of backbench MPs. “It’s already popping up on the WhatsApp groups and people will be raising it with ministers, I’ll put it like that,” they said. “Essentially, a lot of people voted Conservative on the back of a promise to bring numbers down below 200,000, and I don’t think they are going to be hugely pleased if we are now saying that we have a vague intention to bring it down to around half a million. “That attitude of just shrugging one’s shoulders and saying, ‘Well, I have inherited it’ is just not going to cut it. Voters don’t see party pledges as sort of corporate statements.” Asked by political journalists in Westminster on Friday if the prime minister had spoken to the home secretary before making his comments about immigration figures, a spokesperson for Sunak said they worked “incredibly closely” on immigration policy. The No 10 spokesperson added that the prime minister would not “put a number” on his ambition to bring overall migration down but that he would “take stock” of official net migration figures due to be released this month. Other Conservative backbenchers were waiting for the latest figures to be released after data in November showed net immigration was 500,000 for the year to June 2022. Experts believe net immigration figures for this year could be between 600,000 and 1 million, prompting a backlash among Conservative backbenchers. Speaking to broadcasters at the G7 summit in Hiroshima, Sunak said he was “crystal clear” he wanted to reduce immigration. But when pressed on how far, he said: “I’m not going to put a precise figure on it but I do want to bring them down.” The development comes amid signs that Braverman had become frustrated, with the Times reporting that measures she had put forward on immigration had been blocked by cabinet colleagues. In an intervention that was seen as a rebuff to cabinet colleagues calling for an easing of visa rules to boost economic growth, Braverman said in a speech that there was no good reason to bring in overseas workers to compensate for shortages in the haulage, butchering or farming industries. “We need to get overall immigration numbers down. And we mustn’t forget how to do things for ourselves,” she told the recent National Conservatism conference in an address that was seen as part of a veiled future leadership bid. Sunak has repeatedly said he wants to bring down levels of net immigration but also defended the system of legal migration to the UK. • This article was amended on 20 May 2023. An earlier version described Adam Holloway as the MP for Kent; he is the MP for Gravesham, in Kent.