There are concerns for the future of an historic Eltham hothouse - second only to Kew as England's largest - after a university announced plans to sell it off.

The University of Greenwich is selling the Avery Hill Mansion site and its magnificent Winter Garden - a classically-styled Grade II listed conservatory dating back to 1889 but which has recently appeared on English Heritage's at risk register. 

University premises on the site have become rundown, upkeep costs run to around £1m a year and much of the site is now empty since the opening of a new £60m building in Stockwell Street, Greenwich.

To the shock of community campaigners, the decision was announced as a bid was about to be made for £2.9m in Lottery funding - a process which had taken three years and could have seen a programme of improvements at the site.

In a letter to local groups, the university said it had taken the decision "with great regret", adding of the refurbishment plans: "Unfortunately after much deliberation we have come to understand that this isn’t the right proposal for the university, or for the Mansion House site in its entirety." 

It went on: "In parallel with our decision not to progress with the Winter Garden project we have now decided to withdraw completely from the mansion site and we will be looking to dispose of the site as whole, including the listed Mansion House complex. This will offer us the opportunity to release substantial funds to invest in facilities elsewhere on our campuses." 

Now the Friends of Avery Hill park group are calling for any sale of the plot to only be approved if it includes an agreement to restore and maintain the garden.

A Save Avery Hill Winter Gardens Facebook page has already attracted hundreds of members and the group is seeking urgent meetings with the university.

Chairman Councillor Nuala Geary said: "We are saddened to see the university leave such a critical part of the local area which has played such an important role in the tapestry of our community for many years.

"We hope that local people are given the opportunity to be consulted on future plans for the site."