Christian Horner points out where Mercedes made 'mistake' before George Russell disqualification at Belgian GP

Red Bull team principal Christian Horner has pointed out where Mercedes made a 'mistake' leading to George Russell's disqualification at the Belgian Grand Prix.

Russell took the chequered flag at Spa-Franchorchamps ahead of team-mate Lewis Hamilton, but was disqualified after his car was found to be 1.5kg underweight.

Former Aston Martin strategy engineer Bernie Collins believed that the issue stemmed from the loss of rubber caused by Russell's one-stop strategy.

His Mercedes was the only car in the top 10 to attempt a one-stop, with Hamilton and Oscar Piastri behind both on a two-stop.

The disqualification pushed Red Bull's Max Verstappen up to fourth place, and his team principal Horner made a pointed comment when approached by Sky Sports F1's Craig Slater after Russell's punishment was announced.

Horner said: "I'm sure that you would have lost well over a kilo of rubber [from the worn tyres], we saw that on Friday [in practice].

"But you have to carry enough fuel to be able to do the sample. Otherwise you're using fuel as ballast. Really sad news for George, but obviously a mistake in their [Mercedes] calculations."

One other contributing factor to Russell's disqualification was the lack of a 'cooldown lap', which allows drivers to pick up discarded rubber onto their tyres in order to help them comply with the weight limit.

Unlike other circuits on the F1 calendar, drivers do not complete a cooldown lap at Spa because of the length of the track.

Speaking after his disqualification was announced, Russell posted to Twitter: "Heartbreaking... we came in 1.5kg underweight and have been disqualified from the race.

"We left it all on the track today and I take pride in crossing the line first.

"There will be more to come."

F1 returns next month after the summer break with the Dutch Grand Prix at Zandvoort on August 25.