Pathology experts have strongly criticised plans to centralise a service away from St Helier Hospital, a leaked letter has revealed.

Consultants in cellular pathology from Epsom and St Helier, Croydon University and Kingston Hospitals have written to chief executive of Kingston Hospital Kate Grimes with concerns about the proposals to centralise pathology care around a super laboratory at St George’s in Tooting.

If the plans are approved less testing would be done at smaller labs, or "spokes", at each of the three other hospitals in SW London.

The plans have put a £2m pathology laboratory opened at St Helier Hospital in May at risk and have added to concerns key services are being axed from the hospital.

The letter said there was a strong support for maintaining a consultant-led and delivered service at spoke sites with face-to-face advice available.

The consultants slammed suggestions of using teleconferencing or telephone advice saying it would lead to an "unacceptable" deterioration in quality.

They said that clinical risks to patients needed to be highlighted including the potential of longer specimen turnaround time, specimen loss and misidentification during transport.

They also highlighted financial risks and said that St George’s Hospital had no proven track record in providing low cost, high volume cellular pathology.

Geoff Martin of pressure group, London Health Emergency, said: "We share all of the consultants’ concerns. Not only have the risks involved not been properly addressed but recent experience of centralised pathology services, just a few miles up the road in inner-London, has been carefully ignored.

"The plans are risky, financially questionable and would only serve to further undermine the status and viability of Epsom and St Helier as once again we are downgraded to the status of junior partner."

A spokesperson on behalf of the South West London Pathology Board said: "The four hospitals are working together to look at pathology services in south west London and a paper will be going to all the Trust Board meetings in January.

"The programme board is working through a number of issues, but we suggest that if consultants have concerns, they discuss these with their own chief executives directly."