Autistic children in Northern Ireland are waiting almost three years to be diagnosed, it emerged today.
The statistic was revealed as the British government faced fresh demands to boost resources for the condition which campaigners have described as a hidden disability.
Ulster Unionist peer Ken Maginnis uncovered the scale of the waiting lists more than six months after he raised the issue in the House of Lords.
Lord Maginnis, who has a seven-year-old grandson with autism, said: "It is scandalously unforgivable.
"It really is something the Government should be ashamed of." The revelation comes as Autism NI (PAPA) prepares to publish a joint report with its Welsh equivalent.
The charity will use the Whitehall launch this week to call for greater investment to help families cope with the biggest rising developmental disorder in the world.
It is estimated 3,500 children of school age and 20,000 adults in Northern Ireland have autism.
Symptoms can generally be detected from the age of three and early diagnosis is critical to meet the specific needs of youngsters and help them develop.
But inquiries by Lord Maginnis discovered 686 children, suspected of having autism, were awaiting assessment at the end of last year. The maximum wait was 35 months.
The former Fermanagh & South Tyrone MP said: "A parent might see something and suspect Autistic Spectrum Disorder when their child is about three. "If it then takes three years the child will be six before it gets an assessment and could have had two years schooling.
"The maximum wait should be three months, not 35."
Together with early assessment autistic children should have their education tailored to their specific needs and be allocated a dedicated classroom assistant, the peer said. Lord Maginnis also called for a Northern Ireland-wide review of services, as well as increased investment in staff and resources.
Autism is a neuro-developmental disability which disrupts the development of social and communication skills. Half of people with the lifelong condition have learning difficulties.
Dr Claire Hughes has two sons, nine-year-old Aaron and six-year-old Martin, with autism.
Dr Hughes, 41, said: "The psychological trauma of parents who have to wait up
to three years for diagnosis must be horrendous. "The trauma is that they are watching their children and hoping that they don't have it."