Shot! Full on the leg stump from Jaydev Unadkat and picked up through square lg for four runs by Mark Stoneman.

Quite a bright start from Middlesex, who need to do something quite remarkable to catch Yorkshire in the promotion race.

A pause in play now as the umpires inspect the ball.

Is it damaged after an early flurry of boundaries or damp after incessant rain in the last couple of days?

Whatever the reason, the ball is being changed after eight overs.

Nick Gledhill
BBC Essex

Image source, Rex Features

There’s an element of ‘what if’ about proceedings here at Chelmsford but Dean Elgar and Tom Westley provided great entertainment in a stand of 253, a new second wicket record for Essex against Surrey.

Westley, ending the season in prime form, hit 25 fours and a six before he was caught off Yousef Majid, giving the slow left arm debutant his first Championship wicket.

Elgar has completed his fourth century of the season and continues to give the impression that Essex could not have found a more ideal replacement for Alastair Cook.

Essex need a win to have a chance of finishing third. Could a double forfeit be on the cards later?

Just for a moment Jaydev Unadkat thinks he has Mark Stoneman caught low on the drive in the slips but it hasn't been given.

Perhaps pad only there.

Ollie Robinson continues down the hill and Sam Robson moves to 17 with a flick to the leg side for one.

Central Stags seamer Brett Randall comes out to bowl at the one-armed Steve Kirby (still reeling from his bicep injury) as the roller patrols the Somerset wicket for one last time this season (I do not think they will roll it for our potential media v groundstaff XI match this evening!)

Back out at 13:27 BST.

Sussex are clearly trying to attack the stumps here with a full length but Ollie Robinson is a bit too leg side and Sam Robson tucks the ball away fine for two successive fours.

He adjusts his line and the Middlesex opener pushes defensively into the off side.

A good start from Mark Stoneman, who drives Ollie Robinson's fourth ball through cover for four runs.

Jaydev Unadkat is bowling up the hill, conceding just a single to Sam Robson in his first over.

Image source, Rex Features

Essex opener Dean Elgar went to his century against champions Surrey, shortly before Tom Westley was dismissed for a magnificent 135.

The captain hit slow left-armer Yousef Majid to long on to give the Surrey youngster his maiden first-class wicket and end a stand of 253 with Elgar. Essex are 262-2 at lunch.

Durham captain Alex Lees has raced to 95 at lunch in the first session of their game against Kent. His side are 149-1.

After Glamorgan and Gloucestershire each forfeited an innings this morning, Gloucestershire are 22-1 chasing 382 for victory in Cardiff.

And they're finally under way in the match between Leicestershire and Derbyshire. Leicestershire are 41-0.

Adam Lyth edges Luke Procter on a flashing drive, but the ball goes well wide of third slip for four runs.

Lyth pushes the last ball through the covers for no run and that's lunch.

Yorkshire continue to tighten their grip on the second promotion spot but will no doubt hope nothing extraordinary happens with their promotion rivals Middlesex, who have just started their match against Sussex at Hove.

Josh Bohannon and Rocky Flintoff survive until the interval, but they'll have a good deal of work to do this afternoon to keep alive Lancashire's hopes of staying up.

Very much Worcestershire's morning, having added another 61 to their total before removing both Lancashire openers cheaply.

80 overs in the day's play.

Sussex bring in Fynn Hudson-Prentice for Bertie Foreman since the last round.

Just the one change for Middlesex too, with Tom Helm coming in for Noah Cornwell.

Mark Stoneman and Ethan Bamber will be making their final appearances as Middlesex players.

Bamber will join Warwickshire next season. Nothing definite for Stoneman yet but he's surely too good a player not to return to first team cricket next summer.

Sam Robson and Mark Stoneman will open the innings.

Robson will face Ollie Robinson.

Shoaib Bashir gets off the mark with a chipped push just past Felix Organ, Somerset do last the over so we will now play until the final wicket falls or 13:10 BST.

Not a great start from Luke Procter.

His third ball is full outside off and driven through cover for four and four more runs come off the fifth ball, driven through the same region.

That takes Yorkshire to 50 in 12.5 overs.

Ben Sanderson thought he had James Wharton out but that ball appeared to bounced off the boot and it landed short of Gus Miller in the slips.

Just the one over from Justin Broad at the other end and now Northants captain Luke Procter will have a bowl before lunch.

Technically Lancashire could pick up 22 points from this game, rather than the full 24, and stay up. That equates to a first-innings score of 350 inside 110 overs, and then beating Worcestershire.

But they'll need Warwickshire to make less than 250 (zero batting bonus points) in their first innings at Notts and then lose, thus sending the Bears down.

You with us?!

Nottinghamshire have opted not to have a tilt at maximum batting points, concentrating instead on denying the Bears another point for bowling.

It's job done in that regard, with the Bears putting four men around the bat for the 110th over from Danny Briggs but Farhan Ahmed plays him sensibly and Warwickshire will have to settle for just two bowling points.

Sussex have won the toss and chosen to bowl first.

We have a minimum of 80 overs in the day's play.

Middlesex need a big score to stand any real chance of beating Yorkshire to the final promotion spot.