Fashion Police -- The Show Will Go On

Kathy Griffin and Kelly Osbourne tried to derail the "Fashion Police" train by quitting the show ... but the network is keeping it and going full steam ahead ... TMZ has learned.

Sources connected with production tell TMZ ... E! execs have already met to discuss the future of the show and they plan to recast the open spots and possibly create a different show with the same concept.

We're told execs realized Kathy wasn't the star Joan Rivers was and are ready to find new replacements.