In the paper we construct a representation θ : F V Bn → Aut(F2n) of the flat virtual braid group F V Bn on n strands by automorphisms of the free group F2n with 2n generators which does not preserve the forbidden relations in the flat virtual braid group. This representation gives a positive answer to the problem formulated by V. Bardakov in the list of unsolved problems in virtual knot theory and combinatorial knot theory by R. Fenn, D. Ilyutko, L. Kauffman and V. Manturov. Using this representation we construct a new group invariant for flat welded links.Also we find the set of normal generators of the groups V Pn ∩ Hn in V Bn, F V Pn ∩ F Hn in F V Bn, GV Pn ∩ GHn in GV Bn, which play an important role in the study of the kernel of the representation θ.