More than 100,000 people applied, with 58 per cent of applications submitted by people aged 34 and under.
A total of 52,408 applications were submitted on Monday, followed by 64,485 on Tuesday.
The numbers are well above the usual average, which came to around 27,000 applications per day in the last month.
The significant jump reflects a growing public expectation that an election is looming.
Under the Fixed Term Parliaments Act 2011, however, he must secure a two-thirds majority if the poll is to go ahead.
However, Labour have said they will not agree to an election unless the bill blocking no-deal Brexit is passed into law.
In 2017 voters aged 18 to 24 were more likely to vote Labour, while older voters were more likely to vote Conservative.
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Just eight per cent of the people who applied to register in the last two days were aged 65 or over.
But John Curtice, the polling expert and and professor of politics at the University of Strathclyde, warned against drawing broad conclusions from the data.
“I would take any figures about applying to be registered with a large pinch of salt,” he told The Independent.
“This is par for the course.
“Younger voters always apply in greater numbers because they are less likely to be on the register [in the first place].
“Many will already be registered. You cannot infer motivation from those figures.”
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If a snap general election were to take place on 15 October, the proposed date, the deadline for applying to register to vote would be 27 September.
Additional reporting by agencies