The go-live of the new NHS e-referral service has been pushed back from November to spring 2015 after testing revealed a number of defects that "may have remained unresolved" by the launch date.

NHS England and the Health and Social Care Information Centre are currently working with Atos to extend the existing contract for the existing Choose and Book service before it expires in December, but a deal has not yet been agreed.

In April, the HSCIC said the new e-referral service, based on open source technology with a focus on open source standards, would go live in November this year.

However, the HSCIC has now delayed the launch of the replacement service until spring 2015 due to the need for “significant test, assurance and defect resolution activity” to be completed.

Beverley Bryant, NHS England’s director of strategic systems and technology and the senior responsible owner for the e-referrals project, told EHI the launch was delayed after the new system failed several “go/no-go” checkpoint tests over the last two months.

“We initially asked for it to pass by the end of August because we wanted to be confident it would be ready,” Bryant said.

“It was quite close but not close enough, and it wasn’t far enough off that we felt we could delay it at that stage.”

However, two further checkpoint tests in September revealed that issues with the system were still not resolved, leading to the decision to delay the go-live.

“The testing was resolving quite a lot, but it was still bringing up defects and issues, and they weren’t slowing at a fast enough rate so we made the call that we needed to tell people – we couldn’t just keep going and hope we’d resolve it.”

Bryant said testing has been going well, with hundreds of users involved “because we need to make sure it works for them”.

She would have preferred not to delay the project without setting a new go-live date, but said the programme team needed to be sure that the issues were resolved in time.

However, she said a revised go-live date will be confirmed by the end of November, once testing is completed.

The Choose and Book contract was due to expire in December last year, but was extended for one year following a delay in Treasury funding for the replacement service.

Bryant said the extension included a provision for further extensions if they were needed.

She said the organisations are currently working to extend the contract until the end of March next year pending approval from the Cabinet Office, with a view that ensuring the integrity and continuity of the service as “paramount”.

“Not matter how much difficulty it causes and how much it costs, it is vital that we not impact live services in the NHS and we have had strong support for that.”

Ben Gildersleve, the HSCIC’s programme lead for e-referrals, told EHI he had discussed the delay at a user group meeting in Manchester this week and was happy with the response he received.

“Most people in the room were actually very supportive of the direction we’re taking, because when you talk about go/no-go tests, we’re not going to take a huge risk because we’ve got 40,000 patients each day who are using the service.”

Choose and Book was developed a decade ago, after the then-Labour government promised to introduce “airline-style booking” to the NHS.

It was intended as one of a number of new, digital services to make the NHS more convenient.

However, its roll-out was significantly delayed, and usage has stalled at around 50% of referrals.