To put this in context - that's more than what you get if fired for Misconduct.
If someone offered you £10k (plus notice period) to leave Capita would you take it? I'd be tempted.
Not sure of the full facts of the case - but an accountant not wanting to work over financial year end (usually jan/feb) should find another job. Should they get time to decompress before/afterwards - yes.
This is the bit that rang alarm bells for me. Like it or not - if you are considering quoting the Working Time Directive, things are already so bad you should be considering leaving.
*Disclaimer its a given that Crapita are pure evil, that doesnt mean that in every case they are 100% the bad guy.