Ed Miliband, Nigel Farage and Natalie Bennett have reminded their supporters to register so they can vote in the general election.
With just hours remaining until the registration deadline, the Electoral Commission has said there could be up to 7.5 million unregistered voters among the 45 million people who are eligible to cast their vote at the ballot box on 7 May.
Potential voters have until midnight tonight (Monday 20 April) to register and have their say in what is predicted to be one of the tightest elections in a generation.
Electoral Commission chairwoman Jenny Watson said: "It takes just a few minutes to apply to register online, so do it now.
"We don't want anyone to miss out, but if you miss the deadline on 20 April and then try to vote you will be turned away from the polling station on election day. Make sure this doesn't happen to you."
Reminding his followers to register before cut off, Miliband told his Twitter followers that their vote "can help change Britain".
Ukip and Green Party leaders Farage and Bennett also used Twitter to encourage those who were yet to register to do so.
At the last general election in 2010, 65% of the electorate turned out to vote, an increase on the two previous elections in 2005 and 2001 when turnout was 61.4% and 59.4% respectively.