  For every free product decomposition $G = G_{1} \ast ...\ast G_{q} \ast
F_{r}$, where $F_r$ is a finitely generated free group, of a group $G$ of
finite Kurosh rank, we can associate some (relative) outer space $\mathcal{O}$.
In this paper, we develop the theory of (stable) laminations for (relative)
irreducible with irreducible powers (IWIP) automorphisms. In particular, we
examine the action of $Out(G, \mathcal{O}) \leq Out(G)$ (i.e. the automorphisms
which preserve the set of conjugacy classes of $G_i$'s) on the set of
laminations. We generalise the theory of the attractive laminations associated
to automorphisms of finitely generated free groups. The strategy is the same as
in the classical case (see \cite{BFM}), but some statements are slightly
different because of the existence of the $G_i$'s. More precisely, we prove
that the stabiliser of the lamination of a relative IWIP is a
$\mathbb{Z}$-extension of a subgroup that is consisted of virtually elliptic
automorphisms. Note that in the free case, virtually elliptic automorphisms are
exactly the finite order automorphisms of $Out(F_n)$. As a corollary of the
previous theorem, we generalise the fact that the centraliser of an IWIP
automorphism of a free group, is virtually cyclic. As a direct corollary, if
$Out(G)$ is virtually torsion free and every $Aut(G_i)$ is finite, we prove
that the centraliser of an IWIP is virtually cyclic. Finally, we give an
example which shows that we cannot expect that in general the centraliser of a
relative IWIP (and as a consequence the stabiliser of its stable lamination) is
virtually cyclic.
