The European citizens’ initiative aims to achieve minimum 1 million backers before 23 July 2019, a threshold that will force the European Commission to formally consider the proposal.

The initiative founders say that union citizenship is a fundamental status of nationals of member states, a status recognised by the European Court of Justice. But, Britain’s departure from the European Union will, it says, “strip millions of EU citizens of this status and their vote in European elections.”

Its arguments centre around upholding the right to freedom of movement within the EU under certain objective conditions of freedom and dignity to prevent citizens from being used as “bargaining chips in negotiations”.

It would apply to people who have “already exercised their freedom of movement prior to the departure of a member state leaving the Union, and for those nationals of a departing state who wish to retain their status as citizens of the Union.”

The campaigners say that their request is not for a European passport, however, one might be issued as a consequence of such an initiative.

The call comes a year after Luxembourg MEP Charles Goerens’ (ALDE) attempt to amend associate European citizenship was refused. Faced with uncertainty over their rights post Brexit, many Britons living in another member country have opted to acquire nationality in their country of residence. According to a eurostat report, the number of UK nationals who acquired citizenship from an EU member state more than doubled in 2016, from 2,478 to 6,555.

Any EU citizen can support the initiative provided they are old enough to vote in EU elections (16 and over in Austria, 18 and over in all other member states).