Please #ONLY# answer this question if you are absolutely certain of the answer - I won't hold you accountable, but there'd be no point answering it unless you were sure. This question is specific and in relation to Amazon **UK**.

Is Amazon "Prime" delivery as quick as Amazon "Express" delivery? Prime says "One working day", but the people at Amazon didn't seem able to answer my specific question - if I order on a Saturday night, using "Prime" delivery, will the package arrive on Monday, the same as it definitely would with "Express"?

Thanks folks - your help is valued