1: Working sequentially (2,5)
5: French song composed by German boy in study (7)
8: Draw out unknown performer before court (7)
9: Aged TV horse swallows a couple of turnips (7)
10: Oak's first seen on the first of May with its leaves out (5)
11: Consequence of upsetting thug or two (9)
13: Mere mists conjured up by hypnotist (9)
15: Uneven ships cable made from hemp (5)
16: Headstrong stag takes over the marsh grass (5)
18: A CNN host I toasted in 'Post' (9)
20: Forms of robbery involving hoisted flags (4-5)
22: Ultimately develop top demonstration (5)
23: Some engines stop working with less maintenance (7)
25: Swap our mollusc in protest (7)
26: Have sheriff's helpers joined Nazi police (7)
27: Eccentric French composer (a base thief to his family) creates a cloying atmosphere (7)