Now Hamilton to the top, less than two tenths separate the top three. We had a half hour delay, it may well be worth the wait with a thrilling battle for pole coming up in the next half hour.

Sebastian Vettel with work to do to avoid a shock Q1 exit.

Is this a day for what would be only the third pole position of Max Verstappen's career? He leads the way with a 1:16.879 and that is 0.066 better than Bottas and 0.235 clear of Hamilton.

Both Williams in the bottom five, along with Magnussen, Raikkonen and Grosjean. Nine minutes left.

Hamilton up to second, five hundredths slower than Valtteri Bottas. Charles Leclerc is third. Bottas, Hamilton, Perez, Leclerc, Gasly, Norris, Sainz and Verstappen are looking in good shape.

Top work from Lando Norris, up to second, within half a second of Bottas.

Now Valtteri Bottas storms to the top thanks to a 1:17.064. Lewis Hamilton gets hampered but loads of time to sort out a route into Q2.

Jolyon Palmer
Former Renault driver on BBC Radio 5 live

In each of the drop zones it's going to be important for the faster drivers to make sure they get the lap. Turn 1 seems to be particularly troublesome right now.

That's where your midfield regulars, if they get a lap time deleted early on, they could be under pressure - or even Lewis Hamilton as we saw at the Russian Grand Prix in Q2 when he had his lap time deleted. It's important to get one on the board.

Max Verstappen with an early benchmark time of 1:17.670, but Sergio Perez trims that time by 0.071 seconds. Mercedes biding their time.

Good work everyone. And Q1 starts at 14:30.

All 20 take part, 15 advance into Q2. George Russell will be aiming to be one of those 15. Eighteen minutes.

Jolyon Palmer
Former Renault driver on BBC Radio 5 live

This is going to be interesting. Red Bull looking very quick on the mediums but not improving at all on the soft tyre - so that's something they're going to have to look at.

They were looked promisingly quick but then had no pace at then end - but then again not many people did have pace at the end.

Great to see loads of fans in the stands and it looks like they will have a qualifying session to enjoy after all today.

Image source, Reuters

Press the play button at the top to listen to our commentary team of Jack Nicholls, Jolyon Palmer, Jennie Gow and Andrew Benson.

Drivers in cars, we may be good to go at 14:30 after all.

Lee: Just think, if the drivers stayed within the white lines that define the edge of the track then there wouldn’t be any deliberate running over the drain covers...

Debbie Rose: Loose drain covers in several parts of the track? Seems like a track inspection was missed before the race weekend.

Tony D: Is there a time limit before F1 qualifying goes down the drain?

Not sure when they'll pull the plug, Tony!

Andrew Benson
BBC Sport’s chief F1 writer

F1 helpfully replaying incidents of cars hitting drain covers (Button at Monaco in 2016, Grosjean in Malaysia in 2017) with damaging consequences to remind everyone why this is important.

We had an incident in Azerbaijan last year when Charles Leclerc ran over a manhole cover, it then raised and George Russell was the next one to drive over it, and it ripped the floor of his Williams apart.

That happened in first practice and ended that session.

Karen Waddy: Now taking bets on how long it'll be before Albon gets a time deleted for track limits.

Kayleigh: I think Max is gonna become the meat in a Merc sandwich, with Bottas on pole.

Nick Gisburne: Glad to see that Portugal has the same work practices we all recognise - a group of men standing round looking at the job, shaking their heads. What's Portuguese for "I'll have to order the part" or "The tool I need is back at the workshop"?

Chris Doherty: I'm stuck at work till 2.30, any chance they can take a bit longer to sort the drains.

You may be in luck, Chris. As soon as we know, you'll know.