LONDON — The British government said Tuesday it would begin rolling out mandatory identity checks for voters, prompting a backlash from those who say the move could effectively disenfranchise millions.
The controversy, with strong echoes of one that played out across the United States this year, turns on the question of whether identity checks are a reasonable tool to combat electoral fraud or are merely an attempt at voter suppression by another name.
Until now, voters in every part of the United Kingdom except Northern Ireland have been allowed to vote without presenting an ID.
But that will change under a pilot program announced Tuesday by Britain’s Conservative government. A photo ID, such as a driver’s license or passport, will be required in up to 18 different areas across England for local elections in 2018.
If the program is successful, it could be expanded nationwide. Britain is next expected to hold national elections in 2020.
‘‘Voting it is one of the most important transactions you can make as an individual, and in the 21st century many transactions require proof of ID,’’ Chris Skidmore, the constitution minister, told the BBC on Tuesday.
Skidmore denied that the pilot program targets any ‘‘particular community’’ and said the program would help ensure that British citizens can exercise their democratic rights ‘‘regardless of their race or their religion.’’
But critics said the program would disproportionately hurt immigrants and poor voters who lack the necessary documents.
A spokeswoman for the opposition Labour Party, Cat Smith, said that mandating identification ‘‘risks denying millions of electors a vote.’’ She cited data from Britain’s Electoral Commission showing that 3.5 million voters — or about 7.5 percent of the national total — would not have the necessary photo ID.
Katie Ghose, chief executive of the Electoral Reform Society, issued a statement comparing the plan to using ‘‘a sledgehammer to crack a nut.’’
‘‘There is simply no evidence to suggest that electoral fraud is widespread across the UK,’’ Ghose said. ‘‘Where it has occurred, it has been isolated and should be tackled locally.’’
Ghose, whose group campaigns to improve democratic participation, said that ‘‘evidence from the US shows that it’s generally those already most excluded from the political process that are worst affected by strict ID laws.’’
According to the National Conference of State Legislatures, 34 US states have laws requiring that voters show some form of ID at the polls.
Allegations of voter fraud and voter suppression became flashpoints in this year’s US presidential election campaign.
‘There is simply no evidence to suggest that electoral fraud is widespread across the UK.’
Republican-controlled state legislatures in recent years have passed a series of laws making it more difficult for citizens to register and to vote. The changes, Democrats have argued, amount to an organized effort to disproportionately exclude poor and minority voters.
Republicans say the changes are needed to prevent fraud. Following his November victory, President-elect Donald Trump tweeted that rival Hillary Clinton had benefited from the support of ‘‘millions of people who voted illegally.’’
He supplied no evidence, and election-law experts say the claim is baseless.