A Thamesmead gym could be just weeks from closure because of what it calls a "nasty" attempt to force it out.
Crossway Gymnastics Centre has been operating out of Arch 11 in Byron Close for 25 years.
The gym regularly caters for up to 100 gymnasts as well as local residents, and also specialises in training competitors with learning difficulties.
But those who run it have been in dispute with landlords Trust Thamesmead and the group has now been ordered out by July 4 after the trust served it with an eviction notice.
Monika Newton’s daughter Matylda, aged six, currently pays £40 for 24 hours of gymnastics coaching a month.
Ms Newton said: "This is really a very nasty attempt to take what a lot of people have worked on for 25 years and make a profit out of it.
"The people who volunteer here don’t get any reward and they put their own time in.
Left to right: Monika Newton with gym coaches Robert McPaul, Paul Wood, Jo Jameson, Aneika Brown and head coach Tony Nell.
"It is completely not right."
Ms Newton, 36, who lives in Abbey Grove, Thamesmead, says loyalty to founding coach Tony Nell means many of the gymnasts will turn their backs on any new facility.
The lawyer said: "The whole idea of this gym is around Tony training and coaching people for the last 25 years.
"They think they can put someone else in there and the residents will keep coming but they won’t.
"The children are so committed that if we found another location, as long as Tony was coaching, they would go there even if they had to travel."
The gym has set up an online petition calling on Trust Thamesmead to allow it to stay.
Crossway Gym members and coaches do not want to see it close.
Trust Thamesmead says it is seeking another community organisation to run the facility and is not looking to make a profit by renting it out commercially.
A spokesman said: “Trust Thamesmead has supported Crossway Gym for many years.
“However, we have been unable to resolve our concerns about the upkeep of the building and wider governance concerns about the group, leaving us with no option but to issue the group with a notice to leave.
“The community is at the heart of everything we do and we are in discussions with a number of organisations who have outlined their plans to maximise the potential of this community resource.
“The space should provide wider community benefits, through partnership working, and the development of links with local schools and voluntary groups.”