An award-winning Brighton garden project has launched a desperate appeal for donations before it runs out of money to complete an “amazing” new eco building.

As grants stall in the face of nationwide cuts, the Moulsecoomb Forest Garden and Wildlife Project needs a total of £20,000 to complete construction of the building, which will replace a shed gutted in a fire in October 2011.

And its manager says unless the project raises £10,000 before Christmas, work on it will have to finish, raising the prospect of redundancies among the team working on it.

The cash crisis comes halfway through the work on the building, which is using materials such as coppiced wood for the roof and will provide a warm, dry shelter for up to 30 people, invaluable to enable the project to run courses on cold wet days.

Project manager Warren Carter said: “Although I’m spending all my time filling in grant forms, we don’t even hear back from a lot of them. It’s getting harder and harder.”

He added: “Our community gardens are a melting pot of people and our work targets some of the city's most troubled youngsters.

“We've been going nearly 20 years and have got an impressive track record. So we are asking if you can help make us as sustainable as the fruit and vegetables we grow.”

The appeal is being backed by former Secret Millionaire Bradley Reback, who gave £7,500 to the project when he appeared on the TV show in 2010.

This was after he went undercover as a homeless man in Brighton for a week and carried out volunteer work including roof thatching at the site.

Writing to the charity, Mr Reback said: “I still think what you do is brilliant and I love the fact that you are small and focused.

“Some of the larger charities sadly are a total joke.”

Since 1994, the not-for-profit project has transformed a patch of derelict ground off Lewes Road into a wonderland of wildlife in its world garden, heritage orchard, fairytale forest and organic vegetable gardens.

Within it is a large treehouse, an outdoor clay oven, a wattle-and-daub roundhouse, a turf sofa, traditional beehive and a bee garden.

Each week, its visitors include children excluded from school, who can learn skills such as horticulture, carpentry and woodland management.

It also runs an environment club at Moulsecoomb Primary School and is transforming a space at Brighton Aldridge Community Academy.

The project costs about £60,000 a year to run, with around 35% of its income generated by its workers, and grants, donations and income from its Friends scheme.

To find out how to become a Friend, visit http://www.seedybusiness.org/donations.shtml.