The father of a disabled voter had to make special arrangements for him to vote on election day because of access problems at his polling station.
Campaigners want disabled people to be able to vote independently
Mike Williams realised his son Rob, 30, a wheelchair user, would be unable to open an entrance door in order to go to the ballot box in Llantwit Major.
A similar problem confronted voters at two other polling stations in the town.
The Vale of Glamorgan Council said it took the issue of access seriously and would be making improvements.
Under the Disability Discrimination Act, which came into full force in October 2004, people with disabilities have the right to access goods, facilities and services provided to the public.
Mr Williams said this meant his son, and all other disabled voters, were entitled to free access to their polling station.
The 56-year-old noticed problems at three of the four polling stations in Llantwit Major while conducting a survey for the Polls Apart campaign for cerebral palsy charity Scope.
He said entrances designated for disabled access at three polling stations - Ahm Lane, Llantwit Major Cricket Club and St Illtud's School youth club - had heavy doors which could not be opened unaided by wheelchair users or those with mobility problems.
"I wonder how many places in the Vale of Glamorgan are in the same situation, blocking out the disabled?," said Mr Williams, whose son was assigned to vote at the youth club.
"There are 1,500 registered disabled people in the Vale and that's not counting the non-registered who have problems as well.
"There are quite a lot of people who aren't going to be able to vote or have to struggle," he added.
Three of Llantwit Major's polling stations presented access problems
"If they close the doors for disabled people, they have to close them for able-bodied people.
"They have had nearly eight months to get this right and it should have been modified by now."
A spokeswoman for the Vale of Glamorgan Council, whose electoral officers ran polling stations throughout the county, said: "We have spoken to Mr Williams and made arrangements with him so his son can vote.
"We do take access to polling stations for disabled people very seriously and we will take this on board for next year.
"These things are found out by experience and, with new disabled access rule having come in now, we will be making improvements."
Michele Kordell, who is coordinating the Polls Apart access campaign for Scope in Wales, said it was not just about wheelchair users, but that issues like poor lighting could be a problem for people whose sight was impaired too.
"Progress has been made but still a lot more can be done to make it accessible," she said.
"People shouldn't be disallowed from voting because they can't get into the building, they should be able to go independently."