Max Verstappen says there is "no point competing" in Sunday's British Grand Prix if his Red Bull team cannot fix an issue that limited his top speed during qualifying.
The four-time world champion could only claim seventh on the grid at Silverstone, with his struggles highlighted by the fact he was unusually outpaced by his team-mate Isack Hadjar, who was more than a tenth faster in fifth.
The setback comes after Red Bull appeared to have made significant progress when a major upgrade package brought to last weekend's Austrian Grand Prix helped Verstappen to finish second - his best result of the season.
Asked what had gone wrong for him on Saturday, Verstappen told Your Site F1: "Two things - the car balance was not great, but also just a lack of top speed [compared] to the other side of the garage.
"We just had an issue from the first run that just stayed there, and at a track like this when you're lacking top speed, you run out of energy faster, so then in the last sector you also completely die, so it just gets worse and worse, to be honest."
Verstappen's frustration comes amid heavy speculation over his future with the team, after the Dutchman's camp recently held talks with McLaren over a potential switch.
Asked whether the issue was track specific given the contrast in performance compared to Austria, Verstappen appeared to suggest otherwise.
He said: "People come with updates. I said it last week. You might look good now but then when people come with upgrades, they take another step forward and then you're lacking again.
"I think that's a little bit the case, plus on our side the car balance was not good, plus the top speed was not there for whatever reason, which we couldn't fix throughout qualifying.
"So that for me is a bigger worry because that clearly shows that there is a problem."
Verstappen insisted he would only have hope of making ground in Sunday's race if his team were able to repair the top-speed issue that he says left him trailing Hadjar.
Asked about his prospects, he replied: "I don't want to think about that at the moment.
"The people ahead of us are faster anyway, with how I feel at the moment.
"We really need to, first of all, just fix our top speed problem for tomorrow (Sunday), otherwise there's no point competing.
"And besides that, we need to understand why our car balance is not coming together."
Sunday July 5
8.20am: F3 Feature Race*
9.55am: F1 Academy Race 2*
11.10am: F2 Feature Race*
12.55pm: Grand Prix Sunday: British GP build-up*
3pm: THE BRITISH GRAND PRIX*
5pm: Chequered Flag: British GP reaction
6pm: Ted's Notebook
*also on Your Site Main Event
Formula 1 is in Silverstone for a Sprint weekend at the British Grand Prix - live on Your Site F1 and Sky One - with Sunday's race at 3pm.
