The Cabinet Office has gone to market for more suppliers for its cross-government identity assurance (IDA) programme, branded 'GOV.UK Verify'.
The scheme aims to allow people to certify their identity via an external provider, so they can gain access to secure online government transactions.
The new framework is valued at up to £150 million over four years and will see a maximum of ten suppliers win bids to join the five currently signed up to the scheme, according to a notice in the Official Journal of the European Union (OJEU).
The five current suppliers are Mydex, The Post Office, Verizon, Digidentity and Experian. However only Digidentity and Experian are currently being used for an ongoing public beta of the GOV.UK Verify service.
The Post Office and Verizon are due to join shortly, according to the Government Digital Service (GDS), which is responsible for GOV.UK Verify. It is unclear when the final supplier, Mydex, will officially start providing services.
The new procurement process has been delayed. Contracts were originally due to be in place 'in October 2014', according to a pre-tender OJEU notice which came out in April.
Although aimed at central government, the framework has a provision for public sector bodies in the NHS or local government to use it in future.
Suppliers have until 6 February 2015 to submit tenders or requests to participate. The government expects to award places on the framework 'by April 2015', according to the notice.
The Department for Work and Pensions led the first procurement in February 2012. It was originally supposed to be used for Universal Credit but those plans were put on ice as it became obvious the project was facing major problems later that year.
The launch of GOV.UK Verify's public beta in October faced a number of issues, with a number of users unable to certify their identity when trying to access the online Common Agricultural Policy service.
The GDS said it had made changes to the service in response and is using the beta phase to "gather feedback from customers and data to make further improvements".
The government aims for all central government services requiring identity assurance to be using GOV.UK by March 2016.
In the meantime it has set out ambitious plans for over 400,000 people to be using GOV.UK Verify by March. The GDS said a number of government services are due to start using the scheme to certify users between now and then.
These include new online services for tax credit renewals, PAYE and self-assessments, viewing your driving licence, making redundancy payments and the government's troubled Universal Credit scheme.
A Labour Party-commissioned report on public sector IT out last month said the GOV.UK Verify scheme is "running significantly behind the initially committed schedule" and may need to be reviewed by the next government if it is not in a more 'stable' position by next May.