Togo, it's not making excuses for an empire -- although, if you want to frame the EUSSR that way, then that makes anyone who talks about the British Empire in the manner of, say, TTT, more than a little hypocritical. Because *they* are the ones portraying the EU as an invading force, taking away our right to rule.
Except that a) they took nothing away from us that we didn't also choose, as a nation, to give, and b) we're literally just about to have the opportunity to leave it, if we so choose (and if we do choose to leave then we can, and in practice the only one who would stop that happening is the UK government if they chose to ignore the result of the referendum). Also, c) in the one case the "conquest" was achieved through force of arms, and in the other, if conquest there was at all, was agreed according to a set of rules which we had a role in shaping.
None of these is characteristic of an imperialist, oppressive regime. In as much as I am drawing a parallel between the two,it is only to draw attention to the ridiculously overblown hyperbole of some "out" campaigners.