Callum Mackenzie: #bbccricket really letting their man loose with the Chelmsford nightclub references.

Back into the attack comes Stuart Broad and has a huge leg before appeal against Ryan ten Doeschate that looks like it may have nipped down legside and maybe went too high.

Broad looks bemused why Nick Cook hasn't given him that.

Ashar Zaidi slogs one away behind square for another boundary. He could be very dangerous here if he gets going but he swings and misses at the next delivery where the kitchen sink might well have got thrown in too.

Seven runs off the over.

Ashar Zaidi is the new man at the crease to join Ryan ten Doeschate and he gets four from his first ball with a neat flick to fine leg off his hips.

A wicket but still 11 runs off that Samit Patel over.

370 might well be the sort of score Essex are eyeing-up, but it'll take some fireworks to get there...

Niall O'Brien
Ireland wicketkeeper on BBC Radio 5 live sports extra

It's all about how they finish the innings now. This last 60 balls, can they get 120, 130 to get that massive score?

50 for Ryan ten Doeschatepublished at 40.4 overs

40.4 overs

Essex 263-3

Half-century for Ryan ten Doeschate as the Essex captain finds the boundary with a nice stroke off Harry Gurney.

He gets there off 40 balls and he got off the mark earlier with a big six.

Big platform here now for Essex...

Alastair Cook pulls out his lesser-spotted reverse paddle sweep against Samit Patel to add a single.

Tidy over from Samit as just four runs come from it. He finishes with a leg before appeal from another Cook sweep, but probably wasn't pitching in line.

Image source, Rex Features

Been some pretty decent tunes on the Chelmsford PA this afternoon. Think I heard a blast of Crystal Waters - Gypsy Woman earlier that would've been a favourite on the dance floor at nearby Dukes' back in the day.

Bit of a bygone target reference for those familiar with the fine city there....

Harry Gurney meanwhile is trying to cut some shapes with the ball as he's called back into the Notts attack.

Ryan ten Doechate digs out his best yorker attempt and squirts it away for four down to third man. Essex past 250 now with 11 overs to go.

Ben Southworth: This innings is why Cook will never play for England again - going at less than a run a ball since reaching 50! Can't accelerate.

120 odd with 12 overs to go isn't too shoddy though Ben!

Ryan ten Doeschate in boundary action now as he slog sweeps Steven Mullaney for four and then next ball, hammers him through the extra cover region for the same amount.

Not content with that, he makes it three from three with a one-bounce loft through the legside.

Image source, Rex Features

Four fours from four balls sees him pull a full toss, which is called a no ball, to the very same blade of grass.

Misses out on the free hit though which only goes for two, but Essex have added 21 off that over.

Welcome boundaries for Essex as Alastair Cook cuts James Pattinson to the fence for four.

Four more the very next delivery as Cook pulls one through the legside.

Up comes a 50 partnership between this pair and 10 runs come off the over.

Bit of fielding for Billy Root to do for Notts. England captain Joe's brother is on as a substitute and misses out today from the team that beat Somerset after the return of Alex Hales.

Another tidy over from Steven Mullaney as just three come from it. Essex have only managed to add 19 from the past five.

James Pattinson back on to bowl and replaces Stuart Broad.

Broad does some chasing in the outfield to cut off a boundary for Ryan ten Doeschate.

Another tidy over for Notts with just five runs from it, they've cut off the boundaries very effectively in the past few.

Steven Mullaney back into the attack for Notts.

Essex only able to deal in singles as Cook and Ten Doeschate continue to work it round and rotate the strike.

A run a ball off that over.

Stuart Broad into an eighth over from that Hayes Close End. The Chelmsford crowd are no doubt getting 'well-oiled' by now.

Image source, Rex Features

They may also get well-fed too this evening if Essex go beyond 300. The club have teamed up with a well-known Taco brand this season to offer free Tacos to every ticket-holder if the Eagles notch up 300 or more in their 50 overs.

Just the one run though from that over, so keep those Tacos on hold for now....

Rory Taylor: Normally at 30 overs you'd say double the score. For Cook that could mean a Daddy Hundred! Can he accelerate though?

Paul Mackereth: Can't wait for #ENGvSA test series with Chef in form.

Ebony Rainford-Brent
Ex-England batter on BBC Radio 5 live sports extra

When you get one in a crunch match like this at your home ground, these things mean a lot to the crowd and to the team.

He's played with some freedom, he did get fed a bit at the top of the innings but he's played some glorious shots. This is what the big men do, they turn up and deliver.

Image source, Rex Features

Alex Hales is busy covering some yards out in the deep for Nottinghamshire as he sweeps the offside boundary.

He must be wondering what's going on a couple of days after England's Champions Trophy exit. Makes a good couple of stops off Jake Ball's bowling.

Essex add five from the over to bring up their 200.

Stuart Broad continued there for Nottinghamshire during that over that Cook reached his century.

He got one to nibble past Ryan ten Doeschate's outside edge but then his team-mates let him down as they failed to cut off the on-drive that brought up Cook's landmark.

Essex nearing 200 now...