If things stand as they are today, I would have the seniority for a jumbo command in 2007 or 2008. If the retirement age is lifted, and a large number of pilots remain on their current types past age 55, there will be no progression up the seniority list, for up to 5 years.
BALPA seem to have their collective heads in the sand, trying to avoid taking either side.
What has the legislation to do with BALPA? They are working closely with BA trying to resolve the real issues over 2006. I appreciate your only concern is "your" jumbo command. However, bearing in mind that legislation for 2006 effectively bans seniority and pay increments altogether, unless BA is willing to justify them later in court (and be liable if their reasoning is not strong enough), and I think you might find the issue a little bigger than your jumbo command.
Will I have any grounds for legal, or any other action?
I would think being able to sue a company for obeying the law a, errr, little optimistic!