Image caption Hundreds of voters will not be able to vote after filling in their addresses wrongly

Hundreds of voters, believed to be students, have been left unable to vote after failing to register correctly.

It is understood many of the 200 invalid applications are from students in halls of residence in Cardiff.

They received emails on Monday from Cardiff council saying their applications had not been registered because of incomplete addresses.

The authority said it had spent "considerable time" trying to contact those affected.

It said a total of 1,000 people across the city filled in online registration forms wrongly.

The deadline to register to vote in the general election was 26 November.

An NUS spokesman said it was "alarmed" and "unacceptable that this situation arose."

An email seen by the Press Association showed a council staff member explaining it could not deal with the problem "due to the volume of incomplete applications in the final hours before the deadline".

A University of South Wales student, who asked to remain anonymous, said she was not informed her application had been rejected, despite applying a week before the deadline.

"They said it's a problem with large student accommodation blocks, which is slightly worrying," she added.

'Concerns have been raised'

Cardiff council said about 1,000 invalid forms were flagged up by the Electoral Commission.

Of those 800 people had been contacted and have since registered correctly.

But of 200 remaining there were "a number of people living in student accommodation".

A council spokesman said: "Without the full and accurate address, including flat and room numbers, it is not possible to add individuals to the register.

"Everyone registering on the site receives an auto confirmation message that the application has been sent to us, regardless if the information supplied is complete or not.

"We have raised concerns about this issue."

Cardiff council said it was the voter's responsibility to register and there was "no obligation on the electoral registration officer to chase up invalid applications".

Despite this it said "considerable time and effort" was spent trying to contact those affected.

What do the Electoral Commission say?

The Electoral Commission confirmed those who had not registered correctly would not be able to vote.

A spokesman said: "We are aware that Cardiff council is currently dealing with enquiries from a number of students about their electoral registration status ahead of the UK general election.

"We understand that the local electoral registration team has tried to contact as many affected people as possible to clarify their details so that they could be correctly reflected on the electoral register for the poll.

"If anyone has any questions about their registration status, they should contact the local authority directly."