More than 300,000 applications to register to vote were submitted last week, as people rushed to meet the deadline for participation in this year's local elections.
The figure was double the number for the previous week, and four times the level at the start of the year.
More than half (56%) of applications were from people aged 34 and under, while just 5% came from those aged 65 and over.
In total, 322,768 applications were submitted in the week ending April 14, according to government figures.
Nearly 125,000 were submitted on April 11 alone - the day before the deadline for applications to vote in the local elections, which will take place in England and Northern Ireland on Thursday May 2.
The surge in applications might also reflect growing public expectation of other polls in the near future, such as European elections, a second EU referendum or even a general election.
The UK is due to take part in elections to the European Parliament on May 23 - but only if the Government has failed to get its Brexit deal through Parliament by polling day.
The deadline for applications to vote in the EU elections is May 7.
Full details on how to register are at gov.uk/register-to-vote
