Trade union GMB has claimed plans for a new shared staffing structure will see a quarter of jobs cut at Richmond Council by 2017.

GMB said the plans, which will save Richmond and Wandsworth up to £10m a year, will see 400 council jobs lost over the next two years.

However, the council denied any decision had been made about staffing reductions, saying only plans to share a senior management team have been confirmed.

Cllr Tony Arbour, Richmond Council cabinet member for performance, explained that the council has already achieved savings of £30m over the past four years and must save the again up to 2018.

He said: ‘The £30m we need to save is around 20% of our budget. However, this saving is not just about staffing. Together with Wandsworth we will review how our services are delivered across the two boroughs. Savings could be found for example through shared procurement exercises or commissioning.

‘We are very early in this process and more work is needed before we can be clear as to the number of posts that will be impacted. The one thing we do know is that we will have one chief executive with Wandsworth and one senior management team.’

Frank Minal, GMB organiser, said the union would be consulting with members on what action to take. He said: ‘GMB members at Richmond upon Thames Council are stunned and dismayed by the news that a quarter of all Richmond council jobs may be gone by 2017.’