This is a complex situation, and someone needs to sit down with you as a group to go over the details. I would however doubt that you can have any direct complaint over the events of three years ago... but those events might form part of the evidence for a claim of unfair selection for redundancy and ergo... unfair dismissal on those grounds.

There are strict legal rules governing reorganisation and redundancy, but you really need expert advice. Assuming you and your colleagues are not in a Trade Union... the ACAS website has a helpline number and that would be a good place to get initial advice.

ADDED...

If the local Reps aren't up to the job, insist they refer the case to your regional officers. 'raising it with management' is a cop out. Insist on a proper legal opinion.

There doesn't seem to be any violation of either UK or US law in what you posted.

I say making everything illegal is the only way to make a human do the right thing.

Owners of business's can promote who they like. There is no UK law dictating to firms what they can do in your position. We are not yet a totalitarian state and cannot be dictated to by the staff as to how we run our business's.

1. Yes. They can extend her role without advertising it. What they have done is to 'absorb' additional duties into her role - it is common practice during re-organisations or redundancies.

2. If she is the co-ordinator, then her role is different from yours and your colleagues. It appears that they are reducing the number of people doing your role, not hers.

Regarding what happened three years ago, if you did not raise it at the time, then it's too late to raise it now. Besides, favouritism may not be fair but it is not illegal.