http://www.legislation.gov.uk/id/asp/2013/11/schedule/10

SCHEDULE 10Group relief

PART 3Withdrawal of relief

Case where relief not withdrawn: seller leaves group

28

But if there is a change in the control of the buyer after the seller leaves the group, paragraphs 13 to 19 and 22 to 25 have effect as if the buyer had then ceased to be a member of the same group as the seller.