  In this note we give an alternative proof of a theorem of Linnell and
Warhurst that the number of generators d(G) of a polycyclic group G is at most
d(\hat G), where d(\hat G) is the number of generators of the profinite
completion of G. While not claiming anything new we believe that our argument
is much simpler that the original one. Moreover our result gives some
sufficient condition when d(G)=d(\hat G) which can be verified quite easily in
the case when G is virtually abelian.
