Marcus a few questions
1. What is the history? ie why does the council own a community centre and why did it agree to lease it to a charity (was it to save on rates? A group of people were really keen to run it as a charity turned up and asked to do it? It seemed a good idea at the time and it would be cheaper than the council running it itself?
2. Is the charity is an unincorporated one - you say the council is custodian trustee. In this case the lease will be held in trust by the council, which is close to the council leasing its building back to itself? Do the trustees hold contracts (in their own names as individuals) or does the council hold them for it?
3. How much rent does the charity pay to the council?
4. What are the councils plans if the charity folds?
I think that in the case above, what the initial agreement expected is key to any special conditions. If the councillors do not want to give a grant, and the trustees want their lives back, they can hand the building back to the council to sort out, and maybe find some new trustees.