Voters and candidates in some parts of Leicestershire will have to wait until lunchtime on the day after the General Election to find out who their new MP is.

Some returning officers in Leicestershire have decided to start counting ballot papers the morning after the election, rather than on the night.

This year's election must be held by June 3 and they are always held on a Thursday.

Votes cast in North West Leicestershire - a key marginal seat - and Harborough will not be counted until the day after polls close.

Returning officers in Charnwood, South Leicestershire (formerly Blaby), Loughborough and Melton are still undecided. Only counts in Bosworth, Leicester South, West and East are confirmed as taking place on the night, as usual.

A spokesman for North West Leicestershire District Council said: "New laws have been introduced which mean we have to check all the unused ballot papers as part of the verification process. This delays the start of the verification and count."

The decision to delay the counts have been met with concern.

Alistair Jones, a lecturer in public policy at De Montfort University, said: "Election night is like the Superbowl for political obsessives like me.

"Staying up late into the night to discover who will run the country is a tradition that has been around for decades.

"The time at which votes are counted should not be moved for the sake of simple convenience – everything should be done to count votes straight after polls close."

The leader of Leicester City Council, Ross Willmott, is Labour's candidate for North West Leicestershire.

He said: "When candidates have been pounding the streets for more than a month they want to know the result as soon as possible.

"It will be very frustrating to have to go to bed before the outcome of the vote is known."

A Facebook campaign calling on returning officers to "Save General Election Night" has more than 6,000 members.

Peter Wardle, chief executive of the Electoral Commission, has written to returning officers across the country to say it is up to them to decide whether to have a Thursday or Friday count.

He said: "We all enjoy the excitement of election night and we understand the natural wish of candidates to know the result as soon as possible.

"But the responsibility is to make sure the results are accurate and accepted. Nothing is more important than that."

BBC election anchor David Dimbleby said: "I think it's a great pity if councils don't count on the night. With continuous live coverage you get the excitement of particular results and particular people."

Eric Pickles MP, the Conservative Party chairman, has endorsed the Facebook campaign.

He said: "At a time when interest and trust in politics is at such a low ebb, it would be a retrograde step to suck all the interest out of the most important and vibrant part of our democratic process."