PARIS — A satirical documentary film that pits a pair of unemployed garment workers against the billionaire head of the luxury giant LVMH Moët Hennessy Louis Vuitton has emerged as a sleeper hit in France, where it has become a rallying cry against a government proposal to overhaul the labor code.

Since opening on Feb. 24 with little marketing, the film, François Ruffin’s “Merci Patron!” — or “Thanks, Boss!” — has been booked in almost 800 theaters and has been seen by more than 260,000 people, according to its distributor. In France, a viewership of 50,000 is considered a success for a documentary.

Mr. Ruffin credits the American director Michael Moore and his 1989 documentary, “Roger & Me,” for inspiring “Merci Patron!” In the film, Mr. Ruffin stages a number of slapstick efforts to reach Bernard Arnault, the chairman and chief executive of LVMH, similar to the ways Mr. Moore tried to chase down Roger B. Smith of General Motors.

At one point, Mr. Ruffin shows up at an annual meeting of LVMH shareholders, only to be ejected after he wears a T-shirt with the words “I Love Bernard.”