Police were called out after about 50 people staged a sit-in at a polling station in Norfolk.
The protest took place at Watton, part of the South West Norfolk constituency. Voter Sarah Mash told of large queues on each of two visits to the station.
Ms Mash told Radio Norfolk the officer in charge closed the station while people were waiting to vote.
Many disappointed voters would not leave. The officer then called the police. No arrests have been reported.
Ms Mash said: "The gentleman there was quite dogmatic and said there was no way we were allowed to vote despite the fact that some of us had been there for a good hour."
She said after the police arrived the voters decided to end their protest peacefully.