A social enterprise has consulted lawyers after losing the contract to supply GP out-of-hours services in two London boroughs to a Bristol-based company.

Patient Care 24’s chief executive has written to NHS South West London protesting at the primary care trust cluster’s decision to make another organisation “preferred provider” for the contract in Sutton and Merton. It still holds a contract to run services in Croydon.

NHS South West London said it could not reveal the provider’s identity because it was in a 10-day legal “standstill period” before the three-year contract was formally awarded. However, HSJ understands it is Frendoc, a GP co-operative in the West Country which recently lost its contract providing out-of-hours services in South Gloucestershire and part of Bristol.

Patient Care 24 told HSJ a meeting with NHS South West London, at which the reasoning behind the decision would have been discussed, had been cancelled and it had called in lawyers to demand an explanation from the cluster.

Alan Kennedy, Patient Care 24’s chief executive, said: “[The decision] just doesn’t make sense to us and we felt it was unsafe.”

He said Patient Care 24, which received £4m for running services across the three boroughs in 2012-13, had offered to cut the charge for the Sutton and Merton work by 20 per cent.

Patient Care 24 was created after GP co-operative company Croydoc was dissolved in 2010 following a series of governance failures. It has a different executive team but employs the same GPs.

It had provided out-of-hours GPs services across the three boroughs from 1995 to 2010.

In a letter to councillors, MPs, GPs and practice managers, Mr Kennedy said there was no “guarantee this change will be risk-free for patients”.

He added: “As you know, it takes many years to build strong and effective relationships based on mutual trust, respect and goodwill. We believe that this risk [would be] substantially reduced by retaining the existing local London-based provider.”

Mr Kennedy said the loss of relationships built up over a number of years should outweigh a small difference in bid scores. He believes the difference in bid scores was 1 per cent.

HSJ approached Frendoc for comment but it did not respond.

He urged members of the social enterprise to brace itself for dissolution if the cluster went ahead with the move.

NHS South West London said it would not answer questions on the procurement until the contract was awarded.