I need to buy about 70 euros tomorrow, where's the best place to go please?

[GrimbleGrog]

...have left it stupidly late, the eldest is off on a school trip at 6am on Friday.

Post Office and M&S are always my fail safe options!

Post office.

Thankyou, I was dreading the idea of chasing around. So the post office is likely to have them, since it's a small amount?

Never had trouble getting Euros same day, though might be trickier at a small branch. My local small high street had them in. You an phone beforehand to check to save a wasted journey!