Adding levels permission on batch of pages

I’ve got a problem, something I didn’t think about at the outset, in adding newly created levels to the ‘Require Membership’ box on each page.

So for example, we have two membership levels and 100 pages of members-only content.

We then introduce a third level of membership. Now is there any way, apart from going through page by page and ticking the REQUIRE MEMBERSHIP boxes, of adding that new third level across all pages as a batch?