The company borne out of a back-office merger between Havering and Newham councils has saved £7million – but is slightly behind on its target.

Onesource was launched last year, combining HR, IT, fraud and legal teams, among others, to create the largest public sector shared service in London.

Dozens of workers lost their jobs in the restructure, which is expected to save Havering £3.9million by 2018 and £10million across both councils by the following year.

By this point, £7.8million in savings were predicted – and £6.9million have been made. The difference will be met using the £1.3million underspend from the last financial year.

A new report has revealed meeting future targets is going to be “very challenging” but Cllr Ron Ower, Havering cabinet member for oneSource, said it was still on course to meet the overall saving.

He said: “At a time when saving money is more important than ever for local authorities, we’re pleased to say that the creation of oneSource has already saved £6.9million and is expected to deliver the overall savings predicted by 2018/19.

“OneSource is always looking for ways to improve and further reduce costs. This includes looking for additional partners.”

At a cabinet meeting in June, Havering Council leader Cllr Roger Ramsey revealed the authority was looking into possible joint-working with Bexley.

Tony Huff, assistant director of business at oneSource, said shared services are increasingly recognised as a way to find savings.

The report also reveals that as a result of falling behind on targets, an ongoing management action is in place to hold non-essential vacancies.

This means when a person leaves their job oneSource will review whether the position is essential or not before filling it.

“Non-essential” expenditure will also be halted.

The report also reveals the percentage of council tax collected was anticipated to fall this year due to the introduction of the 15 per cent minimum contribution and the first rise in six years, but it has remained similar to last year at 58pc.