Around 14,000 voters were denied a vote at the local elections as they didn't have the right ID, the first official figures show.
Analysis by the Electoral Commission found thousands of people were turned away from polling stations due to the Tory voter ID crackdown which came into force last month.
The watchdog found that 0.7% of people were blocked from voting as they didn't have photo ID - but around two-thirds of them returned later in the day and were able to vote.
However, approximately 14,000 voters - 0.25% - who went to a polling station were not able to vote at all.
And the Electoral Commission warned that "significantly more" people likely did not even turn out because of the policy.
Critics have accused the Government of voter suppression and warned that minority communities were likely to be worst affected.
Last month, former Cabinet Minister Jacob Rees-Mogg suggested the introduction of voter ID was an attempt at "gerrymandering" that backfired against the Tories.
Some 81,033 certificates were issued to people without ID ahead of the local elections - but only 25,000 were used on the day, the commission found.
Labour's Deputy Leader Angela Rayner said people were being "locked out of democracy" by Tory crackdown.
"These strict rules are having a chilling effect on democracy," she said.
“Jacob Rees-Mogg’s admission that this shabby scheme was designed to rig the rules to lock voters out revealed the cold truth behind it.
"Ministers are required to hold a comprehensive review into this discredited policy and there must be no more dither and delay."
Liberal Democrat Local Government spokesperson Helen Morgan branded it an "outrage" that people were being shut out of voting.
She said: “Obstructing people’s right to vote like this in such a disproportionate way is a complete waste of money that undermines our democracy.
“It looks like a transparent attempt at voter suppression by Conservative ministers who are desperate to stop people from holding them to account by any means possible.”
Tom Brake, of Unlock Democracy, said: “Today’s findings are a damning indictment of the expensive, illogical and democratically damaging Voter ID legislation.
"It is plain to see, from what the Electoral Commission have said, that this Voter ID policy stops people who have the right to vote from voting.
"The Electoral Commission say that more work needs to be done to improve it. However, we say that the Government should simply scrap this dangerous policy, before more voters are denied their right to take part in democracy.”
A Department for Levelling Up, Housing and Communities spokesperson said: “It’s vital we keep our democracy secure, prevent the potential for voter fraud, and bring the rest of the UK in line with Northern Ireland which has had photo identification to vote in elections since 2003.
“We welcome the Electoral Commission’s interim report on the May’s local elections which shows that the vast majority of voters – 99.75% - were able to cast their vote successfully and adapted well to the rollout of voter identification in Great Britain.
“These encouraging findings are also reflective of the confidence we always had in the ability of local authorities to implement these changes while continuing to deliver our elections robustly and securely.”
The Daily Mirror launched its Get ID, Get a Vote campaign to raise awareness that the rules have changed.
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