Clue: Second-rate 'Strictly' particip­ant entertaining one and all — such may offer fun at Blackpool? (5,5)
Answer: BEACH BALLS
Explanation: Definition: such may offer fun at Blackpool?
The wordplay puzzles me: the best I can make of it is an envelope ('entertaining') of EACH ('one and all') in B ('second-rate') plus BALLS (Ed, ex-MP, and '* 'S*trictly' participant' – he was one of the 15 celebrities in the 14th. season). Johnny Ball and his daughter Zoë are far more prominently associated with the show – Strictly Come Dancing, to give it its full title (and Johnny, with last place in the 10th. season, might be the best fit for 'second-rate')- but that would leave the final S hanging, and I can find no justification for it as an abbreviation for 'such'.