  We study the possible singularities of isotropic cosmological models that
have a varying speed of light as well as a varying gravitational constant. The
field equations typically reduce to two dimensional systems which are then
analyzed both by dynamical systems techniques in phase space and by applying
the method of asymptotic splittings. In the general case we find initially
expanding closed models which recollapse to a future singularity and open
universes that are eternally expanding towards the future. The precise nature
of the singularities is also discussed.
