  We have performed CDCC calculations for collisions of $^{7}$Li projectiles on
$^{59}$Co, $^{144}$Sm and $^{208}$Pb targets at near-barrier energies, to
assess the importance of the Coulomb and the nuclear couplings in the breakup
of $^{7}$Li, as well as the Coulomb-nuclear interference. We have also
investigated scaling laws, expressing the dependence of the cross sections on
the charge and the mass of the target. This work is complementary to the one
previously reported by us on the breakup of $^{6}$Li. Here we explore the
similarities and differences between the results for the two Lithium isotopes.
The relevance of the Coulomb dipole strength at low energy for the two-cluster
projectile is investigated in details.
