The Leader of the House of Commons, William Hague, has said "we should be concerned" if people haven't been able to register in time to vote for the EU referendum.
The online registration process closed at midnight on Monday, but many people could miss out on voting on June 23 after the site crashed due to last-minute demand.
Speaking to ITV News, Mr Hague said "a lot of attention" should be given to the issue and "everything possible" should be done to cater for those who missed out.
William Hague has claimed Ed Miliband is only calling for a television debate with David Cameron out of desperation to stop the election slipping away from him.
The Commons leader faced down MPs' anger over the Prime Minister's "indefensible" and "craven" refusal to debate one on one with the Labour leader, stressing that former prime minister Tony Blair refused to do so altogether.
Hague hit back, "I think, of what the leader of the Opposition was saying yesterday when he was calling for a debate, which means 'I am desperate because the election is slipping away from me and I have nothing else to ask about at all'. That is the translation of that."
Russia will face more sanctions if they continue to "destablise" Ukraine, William Hague has said.
The former Foreign Secretary told the BBC that Russian President Vladimir Putin is facing a "huge long-term price" for his country's alleged role in supporting separatists in eastern Ukraine.
"The costs to Russia over this behaviour are mounting and will get even higher," he told the BBC.
"If Russia continues to destabilise Ukraine there will be higher sanctions."
Mr Hague said the UK was not planning to send arms to the Ukrainian government following calls from ex-defence secretary Liam Fox.
"We are not planning to send arms to Ukraine - we want to see a diplomatic solution. You have to think very carefully before you send arms into a conflict."
The Conservative Party laid out its proposals for "English votes for English laws" today.
House of Commons leader William Hague said the planned devolution of more powers to the Scottish government creates "imbalances" that do not favour English MPs.
ITV News' Political Editor Tom Bradby reports:
William Hague has unveiled plans that would see English MPs set their own country's income tax rates.
The Commons Leader said the reforms are a "fundamental matter of fairness".
ITV News Political Correspondent Carl Dinnen explains the plans:
William Hague tried to draw Labour further into the English votes debate as he accused them of "betraying" voters as he set out the Conservative blueprint for delivering "English votes for English laws."
However the proposals still face a tough battle with some in the Conservative party who believe the plans are too weak and would make the situation worse by providing nationalist MPs with a "battering ram against the Union".
Under the Tory manifesto proposals - which Mr Hague is seeking to put to a Commons vote before May's general election - policies affecting England alone would be scrutinised by a panel made up only of MPs representing English seats.
A "grand committee" of all English MPs would then have to approve the legislation. Welsh MPs would be included on matters not devolved to the Cardiff Assembly.
A large section of Tory backbenchers are angry that the final - Third Reading - vote on Bills would still include MPs from the rest of the UK, in what they say is a watering down of David Cameron's promise to act.
The deupty leader of Ukip has slammed Conservative palns for English MPs to be given vetoes.
Paul Nuttall says the proposals panders to the culture of "back room stitch-ups."
We cannot have the tail wagging the dog.
It would create chaos where one group of MPs were being pitted against another. It would be cleaner and fairer for English only issues to be voted on by MPs in English constituencies.
It is likely that after the General Election there will be more SNP members of parliament sitting in Westminster whose concern will be Scotland and not what is best for England. In that situation these plans would add layers of process and confusion to legislating and lead to back room deals being made far away from the voters eyes.
Why are the Tories are climbing down for English only votes? Is there already a back room stitch-up?
MPs representing Scottish constituencies would be stripped of the power to "impose" income tax rate changes on the rest of the UK under a parliamentary shake-up planned by the Conservatives.
It would give an effective veto to MPs for seats in England - and Wales on some policies - over matters that are decided north of the border by the Scottish Parliament, but would still require a majority of all UK MPs to pass legislation.
Under the preferred option, only English MPs would consider the amending stages of legislation that relates only to England and have a veto via a procedure known as a legislative consent motion.
William Hague has described how English votes for English laws would work in the UK Parliament.
The former Foreign Secretary told Good Morning Britain that: "If we're proposing to change the level of health spending in England then that does have an affect on Scotland and that is for all MPs to vote on. But if we're voting on how to share out the health spending in England in the different parts of England that should require the agreement of the English MPs."
William Hague said Labour have "learnt nothing from their mistakes" as he helped launch a scathing attack on the party ahead of May's election.
"They are committed from the start to more wasteful spending, more borrowing and higher taxes," the Leader of the Commons said.
"It is in their DNA," Hague added.