South Yorkshire folk have until midnight to register to vote in the UK's historic EU referendum.
Electoral Commission chiefs confirm 1.65 million people have applied for a vote since last month's campaign launch. But millions more have yet to sign up.
Registering online should take about five minutes. People may need their National Insurance number, or passport number if a UK citizen living abroad.
The commission stressed today is "last chance" for people to take part in the June 23 poll.
Those eligible to cast a vote on 23 June - which include British or Irish citizens living in the UK who are 18 or over and Citizens of Commonwealth countries who are 18 or over and who have leave to remain in the UK - have to be on the electoral register to actually do so.
Anyone living in the UK who registered to vote ahead of last year's general election or last month's elections in England, Scotland, Wales and Northern Ireland does not need to re-register if they are still living at the same address. If they have since moved, they must re-register.
Those who are unsure whether they are registered should contact their local electoral registration office while those wanting to vote by post must download the application form and return it to their local office by 5pm tomorrow to qualify. They must return postal ballots by 10pm on June 23, when polling stations close.
To apply to vote by proxy, people need to complete a separate application form, to be returned by 5pm on June 15.
Electoral Commissioners said 226,000 applications to register were received yesterday - second highest single day's total since electronic registration was introduced in 2014.
Its communications director Alex Robertson said there had been an "awful lot" of interest in signing up with 150,000 of Monday's applications coming from people aged under 35.
This figure is expected to be comfortably exceeded today due to publicity such as this with Remain and Leave campaigns leading politicians urging all to make their voices heard.
"This really is your last chance," said Commission Chairwoman Jenny Watson. "If you aren't already registered to vote, you need to do it by the today's deadline or you won't be able to take part in this historic referendum."
At a glance: who is eligible ...
British or Irish citizens living in the UK who are 18 or over
Citizens of Commonwealth countries who are 18 or over and who have leave to remain in the UK
British citizens living overseas who have been registered to vote in the UK in the last 15 years