The film-maker was due to begin working on his big-screen adaptation of Ian McEwan's novel On Chesil Beach this year (10) but the production was postponed until the seasons change.
A spokesperson for Mendes' company Neal Street Productions explains, "It has been postponed. It all happened very quickly. Pre-production work over-ran. There need to be leaves on the trees."
It's the latest career setback to hit Mendes - he was due to step behind the camera for the next James Bond instalment but the project is being held "indefinitely" due to financial woes at MGM studios.