All searches at UK Airports are by consent, you have the right to refuse a search of yourself or your bags. Equally airport security have the right to refuse you admission airside for doing so.
Than refuse and see what will happen. If only one will that person will find him/herself out of work, if all will they will have to do something about it as aircraft can not fly without a pilot. They can ruke you and me as long as we co-operate, once we stop they have a problem.