A tri-borough backroom scheme is set to see one of its member councils pull out entirely by the end of the month.

OneSource initially began in 2014 as a cost-saving partnership between Havering and Newham, with Bexley later joining as well.

But the south east London council has announced its intention to fully withdraw by July 31, with the requirement for a 15 month notification period being waived.

Newham also announced it would withdraw from all financial services provided by OneSource except for those currently provided by the transactional team, treasury and pensions and the oracle systems support team.

Agenda documents released ahead of a Newham Council cabinet meeting on Tuesday, July 14 reveal that a provisional agreement between the three councils was reached at the OneSource joint committee meeting on Friday, June 26. However, it will require the formal agreement of each council before it can be implemented.

The documents state: “These changes will create additional costs for Havering which will lose some of the economies of scale that have been achieved by sharing services.

“Under the partnership agreement between the three boroughs, the two boroughs requesting the withdrawal of services must compensate Havering for the additional costs this change creates.”

It was not specified how much these costs would be.

OneSource’s executive director Simon Pollock said: “OneSource continues to be a successful solution, but above all things, the partnership has the confidence to be flexible to meet our partners’ needs.

“We are sorry to see some of our finance colleagues go but we fully support this change, as OneSource has never sought to seek to impose a particular service model or way of working on anyone. We look forward to our future focus supporting our partner councils across all shared services.”

A Bexley Council spokesperson said: “We have reviewed our future need for finance and assurance services and decided that we will end our involvement in the oneSource partnership with Havering and Newham and bring these functions back under our direct control.

“We have considered the financial implications and they are being addressed in our medium term financial strategy.”

Havering and Newham said they would not be commenting until after the issue had been before their respective cabinets.