(14d) Extemporise after some glad libation. (2 - 3) A _ L _ B .
(17d) Disputed having competed. (9) _ O _ T _ S _ E _ .
(20a) Russian in a fall out about old Russia? (4) _ S _ R.
(26d) Moving Preposition. (4) I _ T _ .
Hi bibblebub-I just wanted to make sure jimby hadn't missed/dismissed your answer which was the only correct one for 20a.
You are good at the crosswords bibblebub. Jumbuck used to be good at these too but I haven't seen him/her around for a while.