Young people and ethnic minorities are in danger of missing out on the chance to vote in the general election, new figures show.

A staggering one in three teenagers are not registered to vote – with just one week until the deadline to do so – compared with only 6 per cent of pensioners.

Non-registration is almost as high among 20 to 24-year-olds (at 32 per cent) and among 25 to 34-year-olds (26 per cent), the Electoral Commission warned.

Meanwhile, one in four black and Asian people are also not registered to vote, the watchdog said, as it highlighted the looming deadline of Tuesday 26 November.

The divide could be crucial on election day, with young people overwhelmingly opposed to Brexit, while older generations are strongly in favour.

Similarly, no less than 77 per cent of ethnic minority voters backed Labour at the last election in 2017, although the Conservatives have strong hopes of eating into that vote on 12 December.

Craig Westwood, the Commission’s director of communication, said: “For some young people this will be their first opportunity to participate in an election, but it’s important they don’t miss the chance.

“Our research shows that young people are less likely to be registered to vote. It only takes five minutes to register to vote online – time that you might otherwise spend waiting for the kettle to boil or for a gym class to start.”

Top 10 marginal seats to watch at the general election Show all 10 1 /10 Top 10 marginal seats to watch at the general election Top 10 marginal seats to watch at the general election North East Fife Currently held by the SNP with a majority of 2 Getty Top 10 marginal seats to watch at the general election Kensington Currently held by Labour with a majority of 20 Getty Top 10 marginal seats to watch at the general election Perth and North Perthshire Currently held by the SNP with a majority of 21 Getty Top 10 marginal seats to watch at the general election Dudley North Currently held by independent, formerly Labour, MP Ian Austin with a majority of 22 LivingInMediocrity Top 10 marginal seats to watch at the general election Newcastle-under-Lyme Currently held by Labour with a majority of 30 Derek Harper Top 10 marginal seats to watch at the general election Southampton Itchen Currently held by the Conservatives with a majority of 31 Rob Candish Top 10 marginal seats to watch at the general election Richmond Park Currently held by the Conservatives with a majority of 45 Robin Webster Top 10 marginal seats to watch at the general election Crewe and Nantwich Currently held by Labour with a majority of 48 Jaggery Top 10 marginal seats to watch at the general election Glasgow South West Currently held by the SNP with a majority of 60 Alec MacKinnon Top 10 marginal seats to watch at the general election Glasgow East Currently held by the SNP with a majority of 75 Christine Johnstone

The low registration rates for young people will alarm Jeremy Corbyn, who benefited from what was dubbed a ‘youthquake’ to wipe out Theresa May’s majority in 2017.

Although that fervour has long since waned, a poll of 1,000 undergraduates carried out before the election was called found that 74 per cent oppose Mr Johnson’s signature policy of Brexit.

Research has also found that Muslim voters could affect the outcome in more than 30 marginal constituencies, as mosques prepare for a nationwide registration drive.

The Muslim Council of Britain (MCB) put the Labour ultra-marginal Kensington, in west London, on top of a list of 31 seats in which Muslim voters could have “high” or “medium” impact.

Also on the list is Dudley North, where the outgoing former Labour stalwart Ian Austin called on voters to back the Conservatives – and Richmond Park, in London, where the Conservative Zac Goldsmith is defending a majority of just 45.

Fourteen of the 31 seats are held by Labour, 14 by the Conservatives and three by the SNP. The MCB has no political allegiance.

The Commission is keen to emphasise how easy it is to register online, by providing only a National Insurance number and passport number.