if i were you, i would cut the main stem completely through as low as possible, eventually it will overload the tree and it could drop onto whatever is below, i had same problem, but left it too late, hence a broken hut, hope it helps, alun

I would do the same. Ivy can be quite damaging to trees by overloading the crown, and the bark sometimes rots or crumbles underneath the ivy stems. Of course, it looks horrible when the ivy goes brown!

But the thicker stems make wonderful firelighters when they've dried.

if it gets too established cutting threw the stems doesn't work so pull off what you can too .