Hundreds of thousands of people could be excluded from voting in a UK general election because of voter ID laws, the government’s election watchdog has said. The laws could have a disproportionate effect on poorer people, those with disabilities and people from minority ethnic backgrounds, the Electoral Commission warned. It said ministers should take urgent action to alleviate these impacts, including drawing up a wider list of documents that people can show to vote and allowing people without ID to have someone else vouch for their identity. Such a damning verdict from the official body for elections risks considerable embarrassment for ministers, who have repeatedly refused to engage with similar concerns from charities and other groups about the impact of voter ID. However, in its own statement about the report, the Department for Levelling Up, which has responsibility for elections, failed to mention any of the criticisms and said the rollout of voter ID had instead been “very encouraging”. The commission’s report, based on a detailed study of the May local elections in England, the first mass use of voter ID in the UK outside Northern Ireland, said the disfranchising effect of the law was very likely to be proportionately greater in a general election. Among people who did not vote in May, 4% said this was because of voter ID. If this figure went up to 5%, it could mean about 800,000 people staying away from the polls at a general election. The study additionally found a disproportionate impact on certain demographic groups. In May, there tended to be a higher proportion of people turned away for lacking ID in more deprived areas than in more prosperous places. The survey of people who did not vote in May found that while 3% overall said this was because they lacked the required ID. This rose to 8% for those who were unemployed and 9% for people with a significant disability. Similarly, young voters or those from minority ethnic backgrounds were five times as likely as the overall average to say they were unable to vote because they took the wrong ID to a polling station. Ministers have faced significant criticism over the limited number of acceptable forms of ID, which include a series of documents issued to older people but almost none issued to younger ones, such as travel passes and student documents. One of the report’s key recommendations is that the current list should be expanded in a way that would help excluded groups to vote. Another proposal is to allow a voter who does have ID to make an “attestation” at a polling station, vouching for the identity of someone who lacks the necessary documents. Any changes should happen “at the earliest opportunity” given the prospect of a general election this year or next year, the commission said, warning more generally that a mass of changes had left the electoral system creaking badly. Although election teams carried off the May local elections without significant hitches, this was only done because of “exceptional efforts and commitment” and in some cases by borrowing staff from neighbouring areas not holding a vote, which would not be possible in a general election, the report said. It reiterated previous warnings from electoral officers that pressures including ID enforcement had made it increasingly hard to recruit polling station staff, with almost a quarter reporting “significant issues”. Florence Eshalomi, the shadow democracy minister, called for a review of the policy. She said: “This extremely concerning report brings into sharp focus the consequences of the Tories’ failed photo ID regulations. It’s wrong that the Conservatives have snatched the ability of legitimate voters to have a say in their services and society.” Rishi Sunak’s official spokesperson said the government would consider the findings of the report, adding: “We have said that we would learn any lessons from this initial rollout.”