Hi, and welcome to the forum.

While I'm not so familiar with Britain's various forms of visas, I've known of at least one case where a pilot moved to the EU with his family and managed to get "recognized" as employed.

It will probably hold more weight if you have worked before as a flight attendant. In the case of the pilot, he was not changing jobs, just his "home base" of operations. If you're applying for a new job, it might work better for you to be applying to a UK-based airline. That way, you'd be paid on the British payroll, with the appropriate social contributions and all. If you're talking to any non-British carriers, you may want to make sure that they can put you on their British payroll so that you're covered by the appropriate social insurances.
Cheers,
Bev