Election success for party once more? (5)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

A + GAIN 10 GLADSTONE : GLAD [pleased] + STONE [14lbs]: William Gladstone: four times Liberal Prime Minister in 19th century 11,29 SOMETHING ELSE : double definition 12 OTAGO : cleverly clued and hidden in prOTAGOnists 13,17 VILLAGE GREEN : anagram of LARGE GLEN I’VE 15 ERINYES: ERIN [poetic name for Ireland] + YES [certainly] : The Erinyes [Greek Furies] were also known by the propitiatory name of Eumenides [‘Kindly ones’] 18 SEC : double definition: SEC[ond]: French ‘dry’ 20 HEWED : ‘feller’ as in ‘tree feller’ – HE WED: this raised a smile 22 EASED UP : EASE [anagram of SEE A + D[emocratic] U[nionist] P[arty] 25 LADETTE : D[emonstrativ]E in LATTE [drink] 26 MINIM : MINI [car] + M[otorway] 27 WRIT LARGE : anagram of WATER GIRL: interesting that we had the unusual anagram indicator ‘swimming’ only yesterday 30 LIE IN WAIT : LIE IN [get up late] + WAIT [hesitate] 31 LOOMS : double definition