Fifteensquared

Top half much harder than bottom half for me, especially because the long phrase in 11 across was new to me. 

Solving time, 25 mins

* = anagram

ACROSS
1  IN CUB A TOR   Tricky – only got it near the end
11 LOVE’S YOUNG DREAM   Eventually worked it out from the anagram (MY NERVOUS OLD AGE)*.     Not sure if it’s a well-known phrase – a quick Google search turned up one of Moore’s Melodies and an association with Shirley Temple.   Good surface.
13 LON(don) + ELY = see (a crossword staple – bishopric)
14 EX + CITED
19 BAN + AN + A   Favourite clue
23 CHAR + T(erm)
24 ALTER + CAT + E (energy)

DOWN
1  HILLSIDE  Excellent cryptic definition – last clue I solved.   From the line of the song “We’ll keep a welcome in the hillside”.
3 PRUNE + LLA (ALL reversed)
8 C(O(duck)+V(very small)ES i.e. SEC = dry (reversed).   Very tricky.
15  C + (Peter)HAIN + SAW    Note the Conservative and politician are separate, so it does not have to be a Con politician.
16 DRACHMAE (ARCH MADE)*   Greek currency now superseded by the euro.  Plural can end in -e or -s or even -i, the anagram letters tell us which.
18 SH + IF before TIER (a row).   Liked that.
20 B (second-rate) + OGOT A (A TOGO “on the up”)
22 D (diamonds – cards) + ICE (diamonds).