First, take a pin to the nozzle.
If that doesn't work, both washer motors on the Cinq are under the driver side front wheelarch liner. One by one pull off the connectors, clean them up, smear with vaseline, try again. If that doesn't do it, swap the connectors over to the other motor, and vice versa. If the rear wash now works and the front doesn't (it'll be front for rear, remember) then you need to pop along to the scrappy and get a "new" one. I don't think they're that expensive.
Otherwise, likely to be an issue with the piping or the stalk.