Rights groups have condemned the chaotic scenario, saying UK authorities have failed to guarantee the vote.

Britons in the EU’s 27 other countries also experienced irregularities, including postal votes “gone missing.”

Hundreds — if not thousands — of non-British EU citizens were turned away from polling stations on Thursday after being told they were not registered to vote in the United Kingdom for the elections of the European Parliament.

The main reason given by polling station workers was that the would-be voter’s form had not been processed in time. However, in some cases, local authorities admitted they had made errors.

“The Electoral Commission, local authorities and the Government in Westminster have failed despite multiple warnings over the last six weeks,” said The 3 Million, a lobby group for the rights of EU citizens living in the UK.

The British Electoral Commission, however, rejected allegations that it was responsible for denying EU citizens residing in the UK their vote, saying the government’s decision to postpone Brexit triggered the chaotic scenario.

“The very short notice from the government of the UK’s participation in these elections impacted on the time available for awareness of this process amongst citizens, and for citizens to complete the process,” said the Electoral Commission.

Around 6,000 asylum seekers live in 35 centres and many complain of poor conditions and lengthy delays in the process. (Aljazeera)