As a Hong Kong permanent resident, he said he felt he was being deprived of a right to the services his son needed.

'If you are going to rely on the government, your child will not have an education at all. There's nothing there for them,' he said. 'There is only one person you can rely on, that is yourself.

'You yourself have to make the efforts to investigate and research [available services] because no one is going to tell you and no one is going to help you.'

Parents have to search for schools, put their children's names on every possible waiting list and dig deep into their pockets to pay for private therapists because of an acute shortage of suitable special education provisions.

And there are no exceptions, whether you are a diplomat or school principal. Parents say waiting in line for schools and services is simply unavoidable in Hong Kong.

Virginia Wilson is chairwoman of Growing Together, an advocacy body representing five NGOs that provide special education services for non-Chinese-speaking children, with more than 200 members.

She said parents became desperate because they felt they had run out of options. Some had chosen to become activists and some simply left the city.

The NGOs represented by Growing Together are the Springboard Project under the Korean International School, Watchdog Early Learning and Development Centre, Rainbow Project Learning Centre, the Child Development Centre at Matilda and the Nesbitt Centre. Watchdog also serves a small number of Chinese-speaking students.

Together, they provide 197 special education programmes such as self-care education and therapies for non-Chinese-speaking students up to 40 years old.

But Ms Wilson said places were extremely limited and waiting lists were at least a year long. Nearly half the places provided by the NGOs are funded by the Social Welfare Department.

According to the Education Bureau, there were about 13,000 special needs students studying in ordinary primary and secondary schools, and more than 7,800 students in 61 special schools as at last September. There are no figures for how many are English or Chinese-speaking.

'If policymakers do not accurately know how many special education needs students there are, how can they be expected to provide appropriate services?' Carsten John, a Growing Together parent, said.

Of the 61 special schools only one - the English Schools Foundation's Jockey Club Sarah Roe School - caters for non-Chinese-speaking students, offering 60 places for pupils unable to cope with learning in a normal school environment.

The ESF also provides 126 places for students with special education needs able to learn in ordinary classrooms, with a waiting list of two to three years. The cost ranges from HK$5,430 for primary to HK$8,500 for secondary places.

A spokeswoman for the Social Welfare Department said there were 2,758 people with special education needs across all ages on Hong Kong social service centre waiting lists as of last month.

In response to an enquiry over the shortage of places, a spokeswoman from the Education Bureau said it was the government's policy to encourage non-Chinese-speaking students to study in the local education system so they could integrate into the community as early as possible.

She also said these students could receive medical services or therapy from the Hospital Authority or Health Department.

If reality was aligned with government policy, however, Kerry Valentine and her family would probably not have had to move away from Hong Kong, leaving behind friends and careers.

'Matthew's education became the most motivating factor to leave Hong Kong,' said Mrs Valentine, a former principal at Korean International School and mother of a seven year-old autistic boy, Matthew. Her Australian husband Michael had lived and worked as an engineer in Hong Kong for about 20 years, but they packed up and moved back to Perth just before Christmas.

'There are many expatriate families who have been in Hong Kong for decades. We are not Chinese, but we are permanent residents. That was our home and we are still entitled to a little respect,' Mrs Valentine said.

'We can't get good extra care, such as speech therapy and occupational therapy, because they are just ridiculously expensive.'

At one point, half of the couple's earnings went towards Matthew's care and it was hard on them financially. Full-time applied behavioural analysis therapy through Autism Partnership cost the family almost HK$50,000 for 120 hours a month. Private speech therapy cost HK$800 an hour.

'[Society seems to] expect every expatriate family to be able to pay a bucket of money, but no one can pay that much and not feel it.'

Matthew did not get accepted into the ESF's special school, nor was he accepted into the learning support programmes within the regular ESF schools, despite Mrs Valentine's nine years spent as head of the English-language section of ESF Educational Services before taking the KIS principal's job.

She said Matthew's condition was not serious enough to get him into a special school but his inability to read, write and speak had ruled him out of the running for a place in a mainstream school.

'The places in ESF for students with special education needs are nowhere near enough,' she said.

'Getting normal kids in there is hard enough, not to mention getting special kids into these schools. Places there are like gold dust; it's virtually impossible.'

Matthew waited six months for the costly private-sector place through Autism Partnership and spent seven months there before switching to the Children's Institute. He was then transferred to KIS' Springboard Project in September 2006, where he stayed until the family left Hong Kong.

'Your hands are tied because you get into this bureaucratic ring of waiting. Every day that goes by is another day lost. It's such a challenge and I felt so alone. There is just no happy solution.

'But the worst thing is that [the shortage of services and school places] encourages people to take advantage of desperate parents. These people can get pretty rich because of desperate parents.

'As [a former] educator I had talked to many parents, and I almost don't want to tell them: if you can't leave, then it's going to be hard.'

She said that as Hong Kong's education system was results-oriented, students with special education needs were often left behind.

'The international schools don't want to muddy the water, they only want children who can perform.

'The entire system is based on standardised testing and geared towards results. My autistic child, who can't write or read, is just not going to do well in your tests.

'If the government says everyone has a right to education, then it needs to strongly legislate to get all children learning.'

Now studying in Australia, Matthew is receiving speech and occupational therapy in the morning and goes to a mainstream school in the afternoon. Everything is free of charge. He should also receive an allowance of A$200 (HK$1,428) a month after re-assessment by Australian authorities.

'It's not much but it's a nice gesture, and it's enough to pay for his swimming lessons. I'm thinking back and wondering, why on earth did we wait this long to move?' Mrs Valentine said.

Hector Huerta and wife Amalia Cornejo have six children. Their two sons - Santiago, eight, and Eduardo, six - are autistic, their four daughters are not.

Mr Huerta is Mexico's deputy consul general for Hong Kong and Macau, and the first thing the family had to confront after arriving in Hong Kong 21/2 years ago was what they called the 'waiting list phenomenon'.

'It was a surprise to learn that Hong Kong is a difficult place for a family like us to adjust to,' Mr Huerta said.

Ms Cornejo said the most difficult adjustment was learning of the one-year or even two-year waiting list for school places. 'Or we can pay a huge amount of debenture, which pretty much ruled out the possibility for us to go into the international schools,' she said. 'We were horrified and we haven't seen [the phenomenon] anywhere else, not even in our country, which is not as developed as Hong Kong. Even in Mexico no child gets left behind without a school.'

But they were among the luckier parents, securing school places after a wait of just three months.

'Unfortunately, not everyone gets the access. I know so many families who are still on waiting lists,' she said.

'I was advised to put Eduardo on all the waiting lists I could find.' He eventually secured a place at the ESF's Beacon Hill School in Kowloon Tong. Santiago fared better and is studying at Lantau International School.

'If you can avoid coming to Hong Kong, it is even better. [Social workers] made it very clear to us at the beginning. We can't afford all these expensive therapists because the Mexican government is only paying for the school tuition and our medical insurance does not cover therapies for autistic children,' she said.

The family lives in Tong Fuk Village on Lantau Island, because of its affordable housing, but the time and money spent on transport is a huge trade-off for them.

Eduardo normally leaves home at 7.30am for the journey to Kowloon and returns at 4.15pm. But three times a week he gets home at 8.15pm after his applied behavioural analysis therapy in Sheung Wan.

'Hong Kong is an interesting place and we really love living here on Lantau Island, but the problem is education,' Ms Cornejo said.

She discouraged family friends who wanted to move to Hong Kong from doing so unless they searched for school places at least a year ahead.

Ms Wilson said Growing Together was calling on the government to boost services and school places for these students, and provide financial aid.

The group is also calling on international schools to set up special education needs programmes, and the government to impose a levy on those that refused to admit students with special education needs.

Ms Wilson said the government should also set up an independent foundation with mandatory rights to oversee special education needs programmes in international schools.

She said the foundation could centralise assessment for non-Chinese-speaking students with special education needs and determine the amount of financial assistance they should receive.

It could also co-ordinate with government departments to secure funding and therapy services at an early stage, and work with international schools to secure placements.

An Education Bureau spokeswoman responded that the government would not micro-manage the operation of international schools, which were commercial organisations and operated on a self-financing basis.

For John Greene and his wife Surinah, the greatest worry now is Padraig's future.

'We have thrown in all the money and paid all the expenses, and struggle to afford the best possible option for our child to earn any little grain of achievement possible,' Mr Greene said.

'We need integrated education but we also need the government to take a strong and leading role to provide more specialised facilities for special needs. This is not going to go away, special needs will always be here.

'I was born here, so I consider Hong Kong home. I don't have the option of running back to Britain or some other place.'