Many thanks for the response to my question.

To ED: Thanks in particular for the links, which provided specific - if
slightly conflicting! - advice.

ie Ohio SU states: "Small trees up to 2 inches in diameter rarely
require staking" - which implies that I probably don't need a stake;
whereas NC SU states: "A general rule of thumb is to provide support for
....container and BB trees over 6 foot or 1 inch or more in trunk
diameter" - which implies that I probably do need a stake!

However, as my tree is grafted, I think I'll be following JB's advice,
and use a low diagonal stake. This won't look too unsightly, and will
have the additional advantage that I'll be able to use the remnants of
the stake I managed to break whilst doing the original planting - so
I'll be able to save myself another 4 quid!

Thanks again

Regards

Paul