Campaign groups have launched a crowdfunding bid to raise money for possible legal action against the British government after they claimed that many EU citizens in the UK were denied a vote in European Parliament elections.
Citizens' rights groups the3million and British in Europe have joined forces to explore ways to try and get compensation for those they say were prevented from taking part in the elections.
The organisations claim thousands of EU citizens living in the UK were turned away from polling stations last Thursday due to their nationality, and UK citizens living abroad found their postal ballot papers turned up late or not at all.
The groups say that by the end of polling day, the hashtag #DeniedMyVote had been tweeted more than 100,000 times.
Co-founder of the3million Nicolas Hatton said: "Imagine being turned away at the polling station in elections you always voted in?
"We should not have been treated like second class citizens and we are calling those who believe in fairness to support us challenge the government in court over the disenfranchisement, discrimination and disrespect of EU citizens in the UK and British citizens in the EU.
"Our voting rights matter, they are part of our fundamental status as citizens and part of our legal and constitutional heritage, protected by EU law. The time has come to stand up for our rights."
Jane Golding, co-chair of British in Europe, said: "Fewer than 40% of UK citizens abroad can actually vote in the UK and administrative problems and cuts to resources have reduced this number even further.
"Brits abroad #DeniedMyVote is a perennial problem in the UK and needs fixing.
"We are asking supporters to help us and the3million explore whether we can challenge this legally through the courts."
John Halford of Bindmans LLP said: "The right to vote is the foundation for all citizenship rights.
"Last Thursday saw a large scale, systematic, openly discriminatory denial of that right.
"The case we plan to bring will show that this is not something the law will tolerate and that there must be accountability and consequences."