1a, 6lets, ?p?s??, Sergeant Major wears down backward jerks.
4d, ??n, American politician in short ready for Japan.
10a, 2words, 4.2. S?n? O?, Forward close in scrum initially, leg behind.
13a, A?t?, Important initiative has the making of an Opposition member.
16d, T?o, Very good retiring from a hot country.
23a, 3words, 4.2.4. A?d? D? C?m?, Military PA in reserve, missing start of service leave.
27d, L?o, Ladies, perhaps, in academy not half upset.
1a spasms
4d sen(ator)
10a send on (on is a cricketing term)
13a anti hidden in the clue importANT Initiative
16d too defn very
23a aide de camp
27d loo - ladies toilet