For the second race in a row Red Bull lost one of its drivers on the opening lap due to a Mercedes as Valtteri Bottas triggered carnage at the start of Sunday’s drama-filled wet-to-dry Hungarian GP.

Having misjudged his braking point, Bottas rear-ended Lando Norris, whose McLaren then smashed into the side of Max Verstappen’s Red Bull. The impact caused substantial damage to Verstappen’s car and ruined his race, with the Dutchman only able to salvage a point in 10th place.

Bottas’ out of control Mercedes went on to hit Perez, who was forced to retire.

"I don't think there was anything we could do," Horner said of the start. "That's the brutality of racing, isn't it?

“I think that, unfortunately, you saw Valtteri make a poor start, he obviously misjudged his braking and he's done a great job for Mercedes in taking out both of our cars.

"There was a significant amount of damage. It cost another engine with Sergio and obviously Max was then hugely compromised.”

To further compound a miserable Sunday, Red Bull fears it has lost another Honda power unit due to the hit that Perez took in the Turn 1 melee.

"It lost all its water immediately," Horner explained. "We'll have to look into it in more detail, but the initial reports are it will no longer be in service.”

Asked if there was any hope of getting to the end of the season without needing a fourth engine for either Verstappen or Perez, Horner replied: “Very little, I'm afraid.

"And that's hugely frustrating for Honda because it's not due to reliability, it's because of accidents that we haven't caused. So they're feeling the brunt of this as well as we are on the chassis side.

“It’s not to be underestimated on the cost cap side, it’s something that does need to be looked at it because it is in a cost cap environment. It’s brutal.”