A number of people with Down's syndrome in Northern Ireland have encountered difficulties in registering to vote in June's European elections, it has emerged.
Robert Kane has voted in previous elections
Robert Kane's parents were told when they tried to put his name forward that "somebody had objected" to his application form.
The 38-year-old, who has Down's syndrome, has exercised his right to vote in prior elections.
His mother, Laura, said she wanted to know who had complained about his registration.
"I'm very cross about it - ever since Robert was born, this sort of thing has happened," she said.
"There is a certain stigma, and people with learning disabilities are treated like second-class citizens."
In the past, one form was given to every household, but now everyone has to register individually.
If someone else signs a form on their behalf, they have to state the reason.
The Electoral Office then sends out a standard letter, asking whoever signed it to confirm that the individual concerned was capable of making their own mind up when it comes to casting their vote.
Denis Stanley, the chief electoral officer, said his office did not make any judgments.
"We don't try to make any clinical judgment whatsoever, but simply take the word of the family or the person themselves," he said.
"If they can make up their minds, they're on the register."
Mr Stanley said anybody could face an objection to their registration to vote.
"The Electoral Register is available, once it's published, at all our offices throughout Northern Ireland, as well as at district council offices," he said.
"Anyone can look at the register to see if they're on themselves, or if they want to object to anyone, for any reason."
The changes in the vote registration system were introduced in an attempt to combat electoral fraud.
People without a passport or driving licence are required to get a special identification card.
Voters who have found it difficult to register can make their views known to the Northern Ireland Office, in a consultation period which ends later this week.
Joan Harbison, of the Equality Commssion, said people with learning difficulties should make their views known to the Northern Ireland Office.
"The fact that this is ongoing at the moment will give people an opportunity to say whether they feel there is more of an impact for people with disabilities or mental health problems than there are for other people," she said.
Mr Kane's parents said they wanted to ensure their son was kept on the electoral register because voting was a matter of citizenship.
They said the current system was discriminatory, and they wanted to meet the person who had challenged their son's right to vote.
A report in December last year said measures to combat voting fraud in Northern Ireland had a negative impact on young people and those in poorer areas.
The Electoral Commission said this measure tended to have an adverse impact on disadvantaged, marginalised and hard to reach groups.
The report also called for a review of the special hearings procedure for those who want to be added to the electoral register.