The Royal Bournemouth and Christchurch Hospitals NHS Foundation Trust stopped taking routine gastroenterology referrals last month but has now extended this. The trust is continuing to accept urgent and cancer referrals, as well as referrals through Choose and Book, for which payment is guaranteed.
More than 500,000 people in Dorset might be unable to receive treatment at their local hospital until the dispute is resolved.
The decision to refuse work came after Bournemouth PCT refused to pay £6.8 million in fees claimed by the trust because the PCT said the trust treated more patients than had been agreed.
The foundation trust says GPs should continue to refer patients. A spokesman said: 'Once a referral has been made, clinicians will assess it and see patients. If the PCT is not prepared to fund treatment, the patient will be informed.'
Bournemouth PCT said funds would be diverted to other hospitals to minimise disruption.