I am trying to draft proof our drop down loft hatch, however I can't see how to get a good seal as its “push to release” click does not hold it tightly enough against the draft proofing strips.
Are there any good solutions?
I've seen solutions that go over top of the drop down-stairs. You can find them by searching for 'attic stair insulation kit'.
If you were to go completely home-made, you can get sheets of rigid styrofoam, then make a box that you can drop over the hole before you put the stairs back up. If the floor is flat and smooth, that might be enough on its own, otherwise you can put down some weather stripping and find a way to secure it down. (maybe eye hooks?)
It sounds like you want to create a firm seal around the hatch.
I would start with something like adhesive foam tape or strip gasket tape. See if you can measure the depth of any present gaps, and try to get a tape thick enough to compensate for that.
(If that doesn't do the trick, posting pictures of the hatch from different angles will help a lot.)