The High Court in London has held that there would be “significant practical difficulties about adopting, especially for this referendum, a new electoral register which includes non-resident British citizens whose last residence in the UK was more than 15 years ago”.

The Judges added: “Electoral registration officers currently retain records of previous electoral registers for a period of 15 years. They have no straightforward means of checking the previous residence status of British citizens who have been resident overseas for longer than 15 years".

The Claimants intend to take the case to the Supreme Court so that all British citizens living elsewhere in the EU can be part of the democratic process to vote in this referendum.

The Claimants' lawyers contend: “We believe that there is precedent for fast-track legislation being put through parliament in a matter of days in response to the court judgment, so there would be no need for the referendum to be delayed if the Supreme Court rules in our favour."

In addition, since this is a vote in a referendum rather than in an election, the Claimants' lawyers argue that there is no need to link the votes of Britons in Europe to any particular constituency in the UK. Possession of a British passport should suffice.