Portsmouth Family Welfare Association, based in Carnegie Library, has been told by the council it will have to pay more if it wants to stay.
The charity – which provides clothing, furnishings, bedding, nursery items and food to poor families – currently pays out around £500 a year.
But The News understands the price could rise to £5,000, as the council seeks to boost its finances. Social enterprise Learning Links has launched a crowd-funding campaign to help come up with cash to cover the bill.
Laura Kameen, of Learning Links, said: ‘We know that the council is having to make cuts, but this is a charity.
‘It helps people who have hit rock bottom and who have fallen through all the welfare networks.
‘People who volunteer there have been through difficult situations themselves.
‘We really don’t want to see this charity go under.’
Tory councillor Steve Wemyss, cabinet member for housing, said: ‘Unfortunately, like all local authorities, the council is facing further cuts to the money it gets from the government.
‘Every year we’re having to make tougher and tougher choices on where to make savings and, because of this, we have a responsibility to make the best use of council assets to protect vital services and jobs. No formal notice has been issued to Portsmouth Family Welfare Association, or terms for a new lease discussed in any detail.
‘Thus far we have only made the tenant aware of our intention to move towards a market rent on any new letting so that we can achieve best value for the tax payer.’