The deadline to register to vote in Britain's 23 June referendum on EU membership is to be extended to the end of tomorrow, a British government minister has announced.
The move - which is expected to require emergency legislation - came after thousands of people were prevented from registering by the original deadline of midnight last night when a government website crashed.
Cabinet Office minister Matt Hancock said: "Following discussions with the Electoral Commission and strong cross-party support expressed in the House of Commons, we will introduce secondary legislation to extend the deadline for voter registration until midnight tomorrow.
"Having taken the decision today, we think it is right to extend to midnight tomorrow to allow people who have not yet registered time to get the message that registration is still open and get themselves registered."
Brexit campaigners accused the government of trying to "skew" the result of the EU referendum by extending the deadline.
The chief executive of the Vote Leave campaign, Matthew Elliott, said the government was "trying to register as many likely Remain voters as possible" amid speculation that thousands of those prevented from registering were younger people who are thought to be more likely to back EU membership.
In a message to supporters, Mr Elliott urged them to get Brexit-backing friends and family to apply for a vote, with the message: "Don't let the government skew the result of the referendum - make sure you and your friends are all registered today."
Downing Street said 214,000 people were trying to use the www.gov.uk/register-to-vote website between 9pm and 10pm last night, but it was not known how many were prevented by the system overload from registering before the midnight deadline.
Amid demands from senior figures including Labour leader Jeremy Corbyn, Liberal Democrat chief Tim Farron and Green leader Natalie Bennett for a deadline extension, ministers went into urgent talks with the Electoral Commission over possible legislative action to allow late applicants to vote.
Prime Minister David Cameron urged people to keep on registering while the situation was sorted out.
In a message on Twitter, he said: "If you aren't registered and you want to vote in this EU referendum you should continue to register at gov.uk/register-to-vote.
"Huge demand caused system overload last night. Urgent discussions with Electoral Commission to try to ensure people who register can vote."
The chairman of the Commons Public Administration and Constitutional Affairs Committee, Bernard Jenkin - a leading Leave campaigner - warned the government was acting on the "cusp of legality" and may be faced with a judicial review if the referendum result was close.
He said the law required the register to be finished and published six working days before the poll, with a further five days in which new entrants on the register can be challenged, when there are just 14 working days before the vote.
"We are on the cusp of legality here. We are now outside the legal framework by keeping the registration open today," Mr Jenkin told BBC Radio 4's World At One.
"If they were to extend the registration for a period longer than this, they are really opening the possibility of a judicial review of the result if it is very close and people feel they have got a cause.
"We are not a banana republic. We shouldn't be making up the rules for our elections as we go along. This is a shambles."
Leading Brexit campaigner Michael Gove said: "These are complex legal waters and I do not want to presume definitively without having looked at the law. But in my heart is a desire to ensure that everyone possible can be given the vote.
"The more people who vote the better. This is a lifetime-defining decision. I would like to see everyone who possibly can and who is entitled to vote play a part in this."
Asked if he feared a higher turnout could damage the chances of a Leave vote, he said: "I am confident that the more people who hear our message, the more will vote to leave."
Alex Robertson, director of communications at the Electoral Commission, said: "No-one should miss out on voting in this historic referendum because of the problem with the government's registration website last night. We said this morning that legislation should be introduced to extend the registration deadline and we're pleased the Government will now be making this change.
"We are urging everyone who is not already registered to vote to take this last chance to do so before the end of Thursday."
Earlier, UKIP leader Nigel Farage claimed that a vote to leave the EU would spell the end for the EU itself within a matter of years.
Mr Farage said he believed that UK withdrawal from the EU would spark an exodus by "many other countries", bringing an end to "the entire European project".
The prediction came in a speech to the European Parliament in Strasbourg, where he won loud and ironic applause from other MEPs when he said he hoped it would be his last appearance as a representative of an EU member state.
"I hope that on June 23, it isn't just Independence Day for the UK," Mr Farage told MEPs.
"I hope it brings an end to this entire project and in a few years' time, we can be sovereign, democratic nation states that work and trade together."
He was applauded by supporters as he departed with a quote from polar explorer Lawrence Oates, who famously left the tent on Captain Scott's doomed Antarctic expedition to walk out to his death alone, with the words: "I'm going out now, I may be some time."
Mr Farage said: "We have in two weeks' time what is to be the biggest event in the history of this project.
"It is the British referendum and it's not just about whether Britain leaves the European Union, because if we make that choice I'm confident many other countries will make that choice too."
Brexit would pose huge problems for rural Ireland
Catholic bishops warn about impact of Brexit
Northern Ireland's Catholic bishops have warned that the outcome of the referendum must not undermine progress to date in building new relationships across the islands of Britain and Ireland.
They say said the reintroduction of border controls in the wake of a Brexit would have profound implications, including the disruption cross-border social, commercial and economic relations.
In a statement, the five bishops with dioceses within Northern Ireland or straddling the border encouraged younger voters in particular to participate given the importance of the EU for their future study and employment options.
They cite Pope Francis' recent praise for the EU founders' "daring" vision to seek shared solutions to increasingly shared problems.
They say the question of economic integration and degrees of political unification are clearly matters of individual prudential judgment.
However, they underline the links between the core values of Catholic social teaching and the Union's founding vision.
They also laud the EU for bringing erstwhile enemies together and urge that this "remarkable achievement" should not be undermined.
