BBC TV documentary/reality series presented by Esther Rantzen whose featured amateurs included singer Sheena Easton and cook Gwen Troake (3,3,4)

I believe the answer is:

the big time

I've seen this clue in The Mirror.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.