Sacha Baron Cohen is backing a planned £1.7 million synagogue project in Cambridge, where he was a student.
Beth Shalom Reform is awaiting final planning permission for its own building, having met in temporary premises for 30 years.
The support of the Borat star was enlisted by his cousin, Cambridge autism expert Professor Simon Baron Cohen, who is a member of the congregation.
Currently based in Los Angeles, the actor sent a message, expressing delight that "Beth Shalom will finally have a permanent shul. As a former student of Cambridge University, I know how important this development will be for future students to celebrate their Jewish identity."
Other celebrity support has come from actress Rachel Weisz, whose mother and sister are Beth Shalom members.
As a former student, I know how important this will be
Shul building committee chair Frank Harris said a deposit had been put down on land in Auckland Road for a shul and community centre, with the aim of opening in time for Rosh Hashanah 2012.
"It's very exciting progress. We have raised about 50 per cent of the money needed and we will seek to raise more once planning permission has been granted, hopefully by the end of March.
"It's a great thing for students here because they've never had a Progressive synagogue to go to before.
"The community is very strong," he added. "When I arrived there were 40-odd members and now we have 250. There are more academics here than I can count - the list goes on and on. Cambridge is growing as a city and it's also becoming a commuter town for London because the rail links have improved so much."