The Electoral Commission said soon after local election polls closed on Thursday that the requirement to carry photo identification “posed a greater challenge for some groups in society”.
Campaigners have reported “countless examples” of would-be voters being turned away from polling stations in the first English elections where photo identification is mandatory.
An Electoral Commission spokesperson said: “We already know from our research that the ID requirement posed a greater challenge for some groups in society, and that some people were regrettably unable to vote today as a result.
“It will be essential to understand the extent of this impact, and the reasons behind it, before a final view can be taken on how the policy has worked in practice and what can be learned for future elections.”
Opponents of the voter ID requirement claimed thousands of people had been turned away.
Tom Brake of Unlock Democracy, who is leading a coalition of groups opposed to the policy including the Electoral Reform Society, Fair Vote UK and Open Britain, said: “Today has been a dark day for British democracy.
“Reports from all over the country confirm our very worst fears of the impact of the disastrous policy which has been made worse by the shambolic way it has been introduced.”
The new compulsory ID rules have sparked criticism that more marginalised communities will face fresh challenges to vote.
The government has said the move will prevent voter fraud and protect democracy. But opposition parties and campaigners claim the plan is based on a false premise that actually amounts to “voter suppression” – locking out millions of voters without ID out of the democratic process.
The Electoral Commission, which was given £5.6 million to carry out a public awareness campaign, has tasked councils with recording how many would-be voters were turned away inside polling stations.
But no record will have been made if greeters deployed outside polling stations turned people away.
The government has estimated that about 4% of Britain’s population – or two million people – were unlikely to have a valid form of photo ID to vote.
Passports, driving licences and blue badges are among the IDs permitted, as are the free certificates that could be applied for ahead of the vote.
Photo ID will be required in England during future general elections under the policy.
The results of the elections will be keenly studied with the prospect of a general election in 2024, with Rishi Sunak’s Tories expected to get a bruising.