Voter ID rules that saw a nurse among those turned away at polling stations must be scrapped, ministers have been told.
People casting their vote yesterday had to show photo identification for the first time - in a move critics described as a brazen voter suppression drive intended to benefit the Tories.
There were multiple reports of people being denied the right to vote, and of rows breaking out as staff tried to enforce the draconian rules.
In Maidstone in Kent, 137 people were turned away for not having correct ID. Officials said 115 later returned, meaning 22 missed out.
It will raise questions on what proved to be a disastrous day for the Tories, with the party losing more than 200 seats so far.
Chris Curtis, a Labour candidate in Milton Keynes, tweeted: “We have just had a nurse, back from a long shift, turned away from the polling station because they wouldn't accept her NHS ID badge…
"You have got to wonder why the government doesn't want our nurses voting.”
Tom Brake, of Unlock Democracy - an umbrella organisation which has called for the change to be scrapped - said: “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."
Labour's Wes Streeting said: "There needs to be a review of how [voter ID] has worked in practice, during these local elections. Because, as far as I'm concerned, one eligible voter turned away and disenfranchised is one too many."
It is unclear how many people were barred, but officials say they will be looking into the figures.
An Electoral Commission spokesman 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."
As early as 11am yesterday, Lib Dem MP Layla Moran said: “We’ve had reports by our tellers of people being turned away at polling stations for lack of correct ID.
“That’s just in my constituency so far. Across the country I’m worried this will be significant numbers and far more than the exactly 0 people found guilty of fraud last year.”
The Mirror reported this week that a 93-year-old cancer sufferer was excluded from voting after having participated in every election since 1950 due to the new photo ID rule.
Just 11p per person was spent by half of local authorities on awareness campaigns for the new Voter ID requirements, research by Unlock Democracy revealed this week.
SNP Cabinet Office spokesperson Kirsty Blackman MP said: “It is deeply troubling that voters were turned away from polling stations and unable to express their democratic wishes all because they were not carrying ID.
“One person being denied their right to vote is one too many and this could pose a serious threat to the upcoming general election. In fact, the next real test of these Tory laws could come even sooner if we are to have a by-election in Rutherglen and Hamilton West.
“It seems the Tory plan to exclude people from voting has worked as certain groups have not been able to cast their vote. The Tories are barring people from taking part in democracy, in a desperate attempt to cling on longer in government.
