David Cameron, Ed Miliband and Nick Clegg are not shy when it comes to selfies, but Britons have been warned not to reach for their camera phones when they enter polling booths to cast their votes tomorrow.

The Electoral Commission advises voters against photography inside polling stations so that they can avoid inadvertently breaching laws on the secrecy of ballots.

Although there is nothing to stop someone taking a picture of their own ballot paper, it is an offence to communicate or publicise this information to anyone else.

Sharing a photographic image of a ballot paper could infringe secrecy requirements under Section 66 of the Representation of the People Act 1983.

Those found guilty of such a breach can face a fine or even six months in prison.

The Electoral Commission said: "The law against releasing information obtained in a polling station is there to protect the integrity of the poll and the secrecy of the ballot.

"Remember that pictures of you before you go into or after you leave the polling station are great to use on social media posts but don't take a picture of yourself inside the polling station as if you post this it could be a breach of the law."

Concerns that the craze could threaten the secrecy of ballots first surfaced last year ahead of local and European elections when it emerged that polling station staff had been told to stop people taking selfies.

Those seeking votes tomorrow have embraced the phenomenon.

The Prime Minister was famously seen leaning in for a selfie with US President Barack Obama and Danish Prime Minister Helle Thorning-Schmidt at Nelson Mandela's memorial service in December 2013.

Both Labour leader Mr Miliband and Liberal Democrat Deputy Prime Minister Mr Clegg have posed with reality star Joey Essex.