Five years in preparation, The Flying Scotsman, is a film biography of Scotland's quirkiest ever world champion, a cyclist who defied convention - and the UCI - to break records.
However, the film's producer has told the Glasgow Herald that unless £1m is found soon, the film will not be made.
Peter Broughan of Bronco Films also produced Rob Roy, a 1995 film which boosted tourism to Scotland. The Flying Scotsman - "another wonderful Scottish hero story," says Broughan - could give a similar filip to cycling.
The cash shortfall is due to the death of one of the partners of Americana Films, a finance company bankrolling 27 percent of the project.
In 1993 Obree won the 4000m pursuit at the world track championships in Norway on "Old Faithful", a bike he had constructed himself, partly from washing machine parts. This bike, and his low-slung riding position, were both later banned by the UCI.
Last year Obree tried to commit suicide.
The Flying Scotsman's producer told the Glasgow Herald:
"We need a fairy godmother or fairy godfather or a group of them to say we will re-occupy the lost territory. It is a very attractive project with strong commercial possibilities, but it has to happen today."
If the film goes ahead, Obree will be played by Jonny Lee Miller, currently track training at the National Cycling Centre in Manchester. The film would premiere at the Cannes Film Festival in spring 2003.