NHS England has announced it will go to open procurement to outsource its £100m primary care support services functions.

The authority said it decided to go to market after receiving legal advice on an offer to take over the service from Shared Services Connected Ltd, a Cabinet Office joint venture.

A briefing document produced by NHS England for PCS staff, published yesterday, said: “Our lawyers have said that we must go to a wider pool of outsourcing options and this is why we are going to open procurement to ensure that we find the best solution.”

An NHS England statement said it had opted for “full market testing” and an open public procurement, rather than restructuring in-house, or transferring functions directly to Shared Services Connected.

It said this would “ensure the best deal for primary care and the taxpayer” and that it had “not been possible to design [an in-house] solution which made the required level of efficiencies”.

Meanwhile, NHS England chair Sir Malcolm Grant has said in a letter to UNISON that it could not legally transfer PCS directly to NHS commissioning support units, as the union had suggested, but was examining whether they could bid for the services through the procurement process.

NHS England has previously said it intends to reduce annual spending on primary care support from £100m to around £60m. It will involve restructuring and removing several hundred posts from the current 1,600 total.

The support services’ functions include supporting cancer screening programmes, maintaining population databases, and coordinating charges for prescriptions and optician and dentist services.

SSCL, a joint venture between the Cabinet Office and business services firm Steria, made an unsolicited bid to take over the service in November 2013.

A spokeswoman for SSCL said: “SSCL is disappointed by the decision not to proceed with our solution for the supply of PCS. We remain committed to supporting NHS England now and in the future to modernise and transform the service by improving quality and efficiency.”

She declined to say whether or not SSCL would bid as part of the open procurement process.

UNISON national officer Nick Bradley said: “This is more uncertainty for 1,800 staff and for the services they provide. It never seemed right that £60m worth of business be transferred to SSCL without a proper transparent procurement. However this opens the door to more companies interested in making a profit out of services such as breast cancer screening.”

The procurement will further delay NHS England’s plan to reform PCS services. Originally the body wanted the work finished by September.