Harry Shindler, a 94-year-old war veteran, and Jacquelyn MacLennan, a Belgium-based expat, fought to change a British law that bars British expats who have lived abroad for more than 15 years from voting in the crucial referendum on June 23rd.
The judgement means some two million British expats living in the EU are barred from casting their vote.
“I'm disappointed but more than that, I'm saddened that after hundreds of years there are still people fighting for the right to vote in democratic Britain,” Shindler, who has lived in Italy since 1982, told The Local.
“The people who are so violently opposed to us having a vote are the same ones who want Britain to leave the EU.
“The MPs who pontificate about Britain leaving the EU have never asked their electors about the vote – they're all talking for themselves.”
Despite the setback, he vowed that “the battle is not over”.
He said he would appeal directly to British Prime Minister David Cameron to push through an amendment to the referendum bill allowing long-term expats to vote, and that campaigners will also appeal the latest judgement at the Supreme Court, the UK's highest court.
Shindler argues that rules governing the UK general elections, the basis for the referendum vote, are not being equally applied.
For example, members appointed to the House of Lords, the upper house of the UK parliament, who alongside British people overseas for more than 15 years are not allowed to vote in a general election, will be able to cast their vote in the upcoming referendum.
Following the judgment Richard Stein, the lawyer from Leigh Day representing the claimants, said: “We are obviously disappointed that the High Court has denied us the opportunity to challenge the decision by the government to exclude British citizens from the EU referendum.
“We now intend to take the legal battle to the Supreme Court, the highest Court in the country, so that all British citizens living elsewhere in the EU can be part of the democratic process to vote in this referendum which will have a very real impact on their lives.
“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.
“Since this is a vote in a referendum rather than in an election 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 be enough.”