Alcoholics and drug addicts who need specialist hospital treatment to kick their habits may have to travel 30 miles into Sussex to get help after Christmas.

The drug and alcohol service inpatient detox service for five south-west London boroughs, including Kingston, has been retendered and won by Sussex Partnership NHS Mental Health Trust based in Crawley.

The current Rowan ward at Springfield Hospital in Tooting run by South West London and St George’s Mental Health Trust (SWLSTG) may be closed.

NHS Kingston said most addicts were currently treated at the Thames Clinic in the Kaleidoscope building in Kingston town centre and only a few cases needing specialist care would go to Crawley.

Ranjit Dhillon, chief executive of Addiction Support and Care Agency in Kingston and Richmond, said: “It is very concerning that people [needing specialist care] don’t have somewhere local to go. This is going to happen all over the country because of Government cuts and big society.”

Suresh Desai, branch chairman for Unison at SWLSTG, said: “It is difficult enough to get them to come to Springfield and, as I understand it, the most vulnerable patients will travel all the way to Crawley for their service.”

The service will begin from early 2012 and have a dedicated inpatient unit at Crawley Hospital with 24-hour medical cover, which is not currently available, en-suite bathrooms and full disabled access.

SWLSTG, which used to provide the service, declined to comment.

Morag Murray, service director for Sussex Partnership NHS Foundation Trust, said: “We already provide a specialist substance misuse service in Sussex and are a preferred and experienced provider of this type of service for other counties.”

Graham McKenzie, Wands-worth borough managing director of NHS South West London, said: “This is the standard of care we believe patients have a right to expect.”

Last month a top GP branded mental health services across Kingston as poor compared to neighbouring boroughs.