Obviously if backup rights are granted in the EULA then there isn't an issue, but you can't actually restrict s.50A(1) rights in an agreement, viz.
S296A.-(1) Where a person has the use of a computer program under an agreement, any term or condition in the agreement shall be void in so far as it purports to prohibit or restrict-
(a) the making of any back up copy of the program which it is necessary for him to have for the purposes of the agreed use;
However, the key point is again "which it is necessary for him to have". In the view of Mr Justice Jacob in Sony v Owen,
The fact is that if you spoil your CD, which has a recording of music on it, you have to go and buy another. The same is true of a CD carrying a game. Backups are not necessary at all.
You might quite reasonably think that this is a bit of a daft comment from the judge, and the academic view is that the judgement in Sony v Owen is flawed, but until a higher court disagrees he's stating the law.