If you're mad enough to want to cross the channel (or an other expanse of water) in your microlight, then good luck to you ....
A holder of an NPPL(M) in a microlight can fly across the channel without special permission as there's a blanket agreement for microlights, but an NPPL(SEP) can't.
So take one TeamEurostar and register it as a microlight and get an NPPL(M) and you can go where you like. Buy the same TeamEurostar, register it as Class A and get an NPPL(SEP) and you can only fly in the UK. That is what I called further back up this thread "stupid bureauocracy". Just writing down annoys me. Roll on some common sense......
B