The number of translates of a closed nowhere dense set required to cover a Polish group

For a Polish group G let cov G be the minimal number of translates of a fixed closed nowhere dense subset of G required to cover G . For many locally compact G this cardinal is known to be consistently larger than cov ( M ) which is the smallest cardinality of a covering of the real line by meagre sets. It is shown that for several non-locally compact groups cov G = cov ( M ) . For example the equality holds for the group of permutations of the integers, the additive group of a separable Banach space with an unconditional basis and the group of homeomorphisms of various compact spaces.