Britons could pay to retain the benefits of European Union citizenship after Brexit, one of the leading figures in the negotiations has said.

Guy Verhofstadt, the European Parliament's lead Brexit negotiator, said he supported the principle of the idea.

Under the plan, Britons could be allowed to pay an annual fee to Brussels in return for keeping many of the benefits currently enjoyed through EU membership.

Mr Verhofstadt, the former Belgian prime minister, said tens of millions of Britons were unhappy at the referendum result and backed plans for the UK to be offered ‘associate EU membership’ status.

However eurosceptics accused Mr Verhofstadt of wanting to create “two classes of UK citizens” and said the proposal was an attempt to undermine the Brexit vote.

Any new trade deal Britain strikes with the EU would have to be ratified by the European Parliament, meaning MEPs could help shape the agreement.

The idea of allowing Britons to adopt EU citizenship has been floated by Charles Goerens, a liberal MEP from Luxembourg, but now has wider backing.