Cryptic Clues

ACROSS
1 In with teachers carrying books around (3,3)
5 William cancels match with a northern guard (8)
9 Worried as smelters get beyond control (10)
10 Many visit ancient Welsh town (4)
11 Poet's material includes nothing against the Spanish (8)
12 Ring Doctor Cecil about Rex (6)
13 Obstruct street with old piano (4)
15 Summarize sailors' pamphlet (8)
18 Guard told to go home before the French return (8)
19 Mark departs with remains (4)
21 Threaten me with broken cane (6)
23 Become still at agent's order (8)
25 I managed in this country (4)
26 What good sides need is part-time management (4,6)
27 Maintain an area of land where game is reared for private shooting (8)
28 Left with a north German golfer (6)


DOWN
2 Duck and goat slaughtered in this place (5)
3 In difficulty immediately (2-3-4)
4 A statement of an intention to inflict damage that implicates King Edward (6)
5 Film venture follows Welsh woman's oriental birds (5,6,4)
6 Lawsuit acting as precedent for reproduction of cassette (4,4)
7 Big hit for Greek philosopher (5)
8 Everybody boycotts this rugby team (3,6)
14 Article on extreme fear in a period of repression in France (3,6)
16 Communist soldier's flag (3,6)
17 Possibly no traces of a forefather (8)
20 Young girl's mother takes Les back (6)
22 Girl grows old in Norway (5)
24 Part of the religious ceremony is hackneyed (5)