A Remain campaigner has been fined £4,000 by the Electoral Commission for buying a referendum advert in a national newspaper without following proper rules.

An anonymous man who called himself Laurence Taylor spent £15,000 on the ad, which was placed in the Metro newspaper on the day before the June 23 referendum.

But he failed to include proper identification details so readers could see who was paying for the campaign ad.

The advert used a pie chart to claim the current levels of net migration of around 330,000 represented an annual population increase of 0.5 per cent and questioned: 'Too many migrants or a failure of government.'

The advert by Laurence Taylor on the eve of the referendum was widely shared on social media by excited Remain supporters

His advert said he had bought the newspaper space because he was 'fed up with the rubbish being talked about immigration'.

The advert was widely shared on social media after it was printed.

The £4,000 fine is the highest imposed by the elections watchdog for this kind of offence - fuelled by the very high circulation of Metro, which is handed to millions of commuters each morning.

The Commission acknowledged Mr Taylor was not an 'experienced' campaigner but insisted it was his own responsibility to follow the rules.

Bob Posner, Director of Political Finance and Regulation & Legal Counsel at the Electoral Commission, said: 'It is important that the funding and spending of campaigners at referendums and elections is fully transparent and that the rules behind this are followed.

All campaigners in the hotly contested referendum had to follow strict rules, from the official Vote Leave campaign (pictured) to the smallest individual campaigners

'Voters must have confidence that there will be consequences if these rules are broken and we produce extensive guidance and work with campaigners to help them, but as our fine to Mr Taylor shows, we will also take action when needed.'

Mr Taylor must pay the fine by January 6 or it will increase by 50 per cent.

On the day the advert was published, Mr Taylor told Metro he did not want to be publicly identified.