Thirty-four-year-old Jenny received the news in a letter after going to see her GP for a referral for a diagnosis.

MP for Oxford West and Abingdon, Layla Moran, raised the ‘extraordinary story' during a members debate on health and social care funding.

Moran told HM: ‘This story is completely unacceptable. People are not getting the support they urgently need.

‘The big issue is that there are no NHS waiting time targets for ASD assessments. This is unlike the physical health sector where providers are given a timeframe for when they have to see their patients. That simply does not exist in mental health services.

‘Whilst the NHS does monitor the size of the waiting lists, there is no downward pressure on these lists to ensure patients can be seen in good time. Jenny's story was a perfect example of this to extraordinary proportions.'

A spokesperson for Buckinghamshire, Oxfordshire, Berkshire West ICB: ‘As commissioners we acknowledge the long waits for adult autism assessments. We are aware of Oxford Adult Autism Diagnostic Support Service's situation and are working with them to find a solution.

‘The demand for autism assessments for adults in the UK has significantly increased in recent years. This rise is largely due to greater awareness and understanding of autism, leading more people to seek diagnoses.'