The facility was set to be sold to a private buyer, who was planning on keeping the pool open for community use.
But yesterday Peterborough city councillors were told that was no longer happening, it would be mothballed instead.
The council has not offered an explanation as to why the sale process has ended.
The pool has been used by thousands of residents in the city over the years, with disabled residents and those with long term health conditions able to gain particular benefit from the facilities.
Speaking to The Peterborough Telegraph, Karen Oldale, St George’s Friends and Service Users’ Lead said it was a ‘vital service’ - and it’s loss was ‘appalling and incomprehensible.’
Karen said; “The City Council’s announcement is shocking and distressing news.
“St George’s is a much-loved, well-used facility. It has over 4,500 registered users from all over the city. They all have disabilities or long-term health conditions and were exercising the pool to improve their health and wellbeing.
“For many it provides a vital service. There is nowhere else they can or would choose to go. Our users were looking forward to returning.
“We would hope taking responsibility to self-manage one’s health and keep as independent as possible, was something the local authority would wish to support and encourage.
“When open, we know St George’s delivered £1,525,000 per year of economic and social value to the city. This is a robust and conservative evaluation. Many of these savings were for PCC, especially in Adult Social Care.
“We know the council’s financial situation, so when a health professional came forward over year ago wishing to buy St George’s and to refurbish the pool for his own clients and the community’s use, it seemed like a win-win.
“In contrast , the council ‘s decision now, after a year, to not proceed with sale – despite buyer having remained keen - and ‘mothball’ St George’s instead, is the most appalling, incomprehensible loss.
“This will have a devastating effect on some of the city’s most vulnerable residents.
“I think it’s an incredibly sad day that reflects poorly on Peterborough.”