Britons could pay to retain the benefits of European Union citizenship after Brexit under plans being considered by MEPs.

Guy Verhofstadt, the European Parliament's lead Brexit negotiator, said he backed the proposal to allow UK citizens to "opt in" individually to EU membership.

Under the scheme, Britons would pay an annual fee to benefit from free movement around the EU, the right to reside in other European countries under existing rules and the right to vote in EU elections.

"Many say 'we don't want to cut our links'," Mr Verhofstadt told The Times. 

"I like the idea that people who are European citizens and saying they want to keep it have the possibility of doing so. As a principle I like it."

Charles Goerens, an MEP from Luxembourg who put forward the idea, says the scheme could even be free for Britons.

He said: "If it is adopted, it must be a voluntary request made by each UK citizen.

"It was thought at the very beginning that they should have to pay a fee but that is a detail. Paying a fee or not is not the essence."

He added: "Between 15 and 30 million British citizens deeply regret Brexit. 

"My amendment was tabled in order to get European citizenship for those British citizens who want to keep their citizenship."

MEPs will vote on the proposals by the end of the year, but any Brexit deal with the UK would have to have the agreement of the leaders of the other 27 EU nations as well as the European Parliament.

On the chances of the proposal being voted through, Mr Verhofstadt admitted: "I don't know if it will fly or not."

He added: "There are big differences of view here in the parliament."

Brexit-backing Conservative MP Andrew Bridgen claimed the plan is "an attempt to create two classes of UK citizen and to subvert the referendum vote."

He told The Times: "The truth is that Brussels will try every trick in the book to stop us leaving."

It comes as former prime minister Tony Blair suggested Britons could stop the process of leaving the EU if they disagree with the terms.

He said voting to leave was "like agreeing to a house swap without having seen the other house".

Meanwhile, the Taoiseach has told Sky News it will be "impossible" for the UK to agree a full Brexit deal within the two years set out in Article 50.

Enda Kenny said a Brexit transition deal between the UK and EU was "inevitable".