I don't really want to go back and talk about Oscar but I don't think we should ever forget the way he treated his staff, and still does! Being a bit of an employment law 'anorak' I have given this matter some considerable thought.
First of all, Oscar's staff have probably been employed by him since some time in 2007 when Oscar was first elected; this means that they have been employed for over 2 years which gives them full employment protection. The second question is, what is their employment status now? As far as I can see they are still employed by Oscar, they haven't been consulted about redundancy and they haven't received a letter dismissing them... so keep turning up for work, and if he stops paying you, you probably have a claim to Employment Tribunal for 'Unlawful deduction from earnings.'
Thirdly, we have the prospect of redundancy which is a form of dismissal which is lawful but only if certain conditions apply i.e. their job ceases to exist. Now you could argue that that is the case here; but has it?, Oscar is still an AM and he still needs staff so the job still exists! When making some one redundant the employer needs to consult with employees and needs to follow the ACAS Code of Practice. Failure to follow and comply with ACAS guidelines allows a Tribunal to increase an award for compensation by 25%. Therefore the chances are that any attempt at making the staff redundant could amount to unfair dismissal. Oscar may be in breach of the code of practice.
Fourthly, what would staff be entitled to? As a minimum those employed since 2007 would get 1 week's pay for each year of service (more if over 42 yrs), 1 week's notice for every year of service or pay in lieu of notice, holiday pay and of course pay for sitting round waiting for Oscar to decide which is the least expensive option for him! All this will be increased by Employment Tribunal but don't expect too much, compensation awards will depend on 'loss' to the individual rather than compensation as such.
Next steps should be to speak to ACAS and then seek detailed advice from their Union's legal team or Citizens Advice Bureau, who will probably advise staff to submit a joint grievance letter against their treatment by Oscar. Sooner or later staff will probably have to accept they have been dismissed and at that point should submit a joint letter to Oscar appealing against the dismissal. Staff should not delay submitting a form ET1 (Claim to Employment Tribunal), they have 3 months from the relevant date which I suggest is 3 months from the date that Oscar defected.
People like Oscar shouldn't be allowed to treat their employees in such a manner, so go for it!
WARNING - This is not definiative legal advice these are just my thoughts on a situation of which I am not fully aware of the facts or any individual's personal circumstances.