Plans to sell a sorting office have put 200 jobs at risk.

Council officers have revealed Royal Mail plans to sell its Wimbledon delivery office – which handles mail for the SW19 and SW20 postcodes – within the next decade.

A union spokesman said staff knew nothing of the idea and accused Royal Mail of “cloak and dagger”

behaviour.

News that the Cranbrook Road site was up for sale came when it was featured in Merton Council’s new list of potential development sites in the borough, the sites and policies development plan.

In a bid to encourage regeneration, the authority has listed 63 key sites whose owners have expressed an interest in development – and launched a public consultation to get residents’ views.

Greg Charles, London south-west branch secretary of the Communication Workers Union, said: “Something cloak and dagger seems to be going on. There’s no smoke without fire.”

Mr Charles said about 200 people were employed at the site. He said in the last few years Royal Mail had closed two similar centres in the area and relocated its work to a site at Nine Elms in Battersea.

This centre itself is scheduled to close this year in a bid to save money.

In 2009, a strike temporarily closed the Wimbledon sorting office, and left Royal Mail employees sorting letters and parcels in the street.

A Royal Mail spokeswoman said she was not aware of any plans to sell the site.

But a council officer confirmed that all of the sites included in its list appeared because their owners had showed a firm intention to sell them in the next 10 years.