What IceMaiden has said is true, though it is worth your friend talking to ACAS about it.
http://www.direct.gov.uk/en/Dl1/Directories/DG _10010857
Some employers do this (but it's rather mean), and there is nothing illegal about it - your friend is choosing to leave before the redundancy has taken effect. Currently all the impacted employees are under notice of dismissal on the grounds of redundancy - until the company writes the letter to each member of staff confiming the redundancy and the date of termination of employment.
He can try and negotiate of part of the payment, decline to join Comet and stick it out with Curry's until the bitter end - taking as much time off as he can for interviews, or issue a counter notice to his employer, leave (irrespective of what they say) then try to take them to an Employment Tribunal to 'prove' his case.
My name is not Chris, by the way, IceMaiden. BM