LONDON — 16- and 17-year-olds will be able to vote in the next U.K. general election, the British government announced Thursday.

The change marks the fulfillment of a Labour manifesto commitment and will bring U.K.-wide elections in line with those in Scotland and Wales.

It was announced as part of a major shake-up of the U.K.’s electoral system that will result in a significant expansion of the franchise, alongside a loosening of voter ID rules and stricter campaign finance rules on foreign donations.

The government called the move the “biggest change to U.K. democracy in a generation,” highlighting that young people “already contribute to society by working, paying taxes and serving in the military.”

While the decision is expected to broadly benefit center-left parties, the precise impacts of the change are less clear.

Polling of 16-to-18-year-olds conducted by Merlin Strategy and featured in the Financial Times indicated that about 33 percent of the cohort would vote Labour, followed by 20 percent voting Reform and 18 percent opting for the Green Party.

Political scientist John Curtice told POLITICO in an interview that the political impact of the change would be “marginal,” estimating that the new bloc of voters —already less likely to vote — would add between three and three-and-a-half percent to the total electorate.

Curtice said, however, that “age is the biggest demographic division in our electoral politics” and that younger voters would be “likelier to vote for Labour or the Greens” than Reform. “The one party to celebrate are the Greens,” he said. For Labour to “fully benefit” from the change, they would have to “fend off a challenge from the Greens,” Curtice said.

The opposition Conservatives criticized the “rushed” announcement, with Shadow Communities Minister Paul Holmes claiming Labour’s unpopularity was “scaring them into making major constitutional changes without consultation.”

Nigel Farage, leader of the populist-right Reform UK party which is leading in national opinion polls, told ITV News he was opposed to extending the franchise even though it would mean “we get lots of votes.”

“I don’t think you should be able to vote in an election unless you’re also eligible to be a candidate, and I don’t think 16-year-olds should stand for Parliament,” he added.

Announcing the change, Deputy Prime Minister Angela Rayner said the government was “taking action to break down barriers to participation that will ensure more people have the opportunity to engage in U.K. democracy.”