The man at the centre of the tug of war, Mushtaq Ahmed, appeals - unsuccessfully - against Darren Maddy at Hove © Getty Images

There was no love lost between leaders Sussex and Warwickshire at Hove where the toss was delayed for 15 minutes after Sussex objected to the inclusion of Nayan Doshi in the visitors' starting XI. Eventually the ECB ruled he was inelgible and so he had to stand down. The animosity between the sides was even more apparent when Sussex issued a terse statement confirming that Mushtaq Ahmed had been approached by Warwickshire. On the field, Mushtaq and his Pakistan colleague Saqlain Mushtaq took all six Warwickshire wickets to fall as the visitors eased to 346 for 6. Ian Westwood and Darren Maddy (53) put on 114 for the first wicket and then Westwood and Kumar Sangakkara (59) 114 for the second. Westwood's dismissal for 110 shortly before tea initiated acollapse in which four wickets fell for 11 runs, but Warwickshire recovered to end the day on top.

Surrey's reshuffling for their crunch relegation battle at Canterbury paid early dividends with two wickets for debutant Chris Jordan as Kent stumbled to 66 for 4 by lunch. Jordan, who has been tipped for England, took two top-order scalps. Harbhajan Singh then ripped through with five to dismiss Kent for 150, Rob Key ever-reliable - but left stranded - with 75 not out. By the close Surrey had reached 148 for 4 with Mark Ramprakash unbeaten on 57.

A hundred from Michael Carberry and 96 from John Crawley put Hampshire on top against bottom side Worcestershire at The Rose Bowl where they closed on 350 for 5. Worcestershire fought back well - at tea, Hampshire were cruising on 222 for 1.

Yorkshire and Lancashire face off at Headingley on Thursday.

Michael Carberry celebrates his eighth first-class hundred - he made 116 for Hampshire against Worcestershire © Getty Images
There were runs a plenty at Trent Bridge as Nottinghamshire were bowled out by Somerset in two-and-a-half sessions but not before Stephen Fleming's 145 had steered them to 350. They had been going well at 151 for 2 before Andy Caddick took two wickets in as many balls to start a middle-order slide, but Fleming, who was last out, and Nadeem Malik put on 83 for the last wicket. Somerset lost Neil Edwards in reaching 83 for 1 at the close.

Essex's promotion bid wobbled slightly at Southend as they slipped to 36 for 3 in reply to Gloucestershire's 278. On a pitch where runs are likely to be at a premium, the visitors squandered a good start by Kadeer Ali (65) and Craig Spearman (75). Their partnership finally ended on 114, Ryan ten Doeschate holding on to a Mark Waugh-type catch off James Middlebrook, and from there the innings fell away on a surface already helping the spinners. Jon Lewis and Steve Kirby took late wickets to add to Essex's problems.

Bottom side Glamorgan recovered from 58 for 3 to close on 294 for 7 against Northamptonshire at Colwyn Bay. A fourth-wicket stand of 155 between Richard Grant (79) and David Hemp (82) formed the backbone of the innings.

Leicestershire's match against Derbyshire starts at Grace Road on Thursday.