You ask a reasonable question, I have long been of the view that BALPA as a singular entity would be better if subsumed into Unite, at present just one legal finding against it could bankrupt it which may explain their timidity. As part of Unite it would also have access to greater resources of legal opinion and negotiators.
However, as things stand, any pilot wishing to join Unite will probably be directed to BALPA. It would be up to the members of BALPA to decide its future.
I know of the IPA but do not see them as serious players, their name is the same as an outfit from across the pond but they are not related, DHL recognised them but only to keep BALPA out, that may say something. I severely doubt that they could give greater representation than BALPA but have read insufficient.
Bruce Wayne - I am sure you meant "principal" instead of "principle" but maybe not, if not then excuse me for underestimating your ability to make a play on words. And there was me thinking you were just a short sighted dogmatist. However, re your dig at the Labour Party, was it not Gordon Brown who spoke out against the strike? Hardly the words of a rabid lefty I think.