Tensions are heating up between title contenders Mercedes and Red Bull.

In Austria, it became clear that the fight this year would not just be between their respective drivers Lewis Hamilton and Max Verstappen.

On Friday, Red Bull launched a protest against Mercedes' innovative 'DAS' steering system.

And on Sunday, the energy drink owned outfit provided new camera evidence to the FIA that led to Hamilton losing his front row grid position over a yellow flag violation.

"Saturday was the only day that Red Bull didn't protest against us," Mercedes team boss Toto Wolff said.

"I think the protest on Friday was fair play, but not the one on Sunday. If you come back on Sunday morning to reverse a decision from yesterday with new evidence, that is allowed under the rules.

"But it is clear that the gloves are off," the Austrian is quoted by Speed Week.

Wolff's Red Bull counterpart Christian Horner was also critical of Hamilton's driving, when asked if Alex Albon could have been more cautious in trying to pass the six-time world champion last Sunday.

"Maybe you should ask Lewis what he can do differently," he said, reminding reporters that Hamilton and Albon have clashed in two of the last three races.

"Ultimately it was just a misjudgement by Lewis, but it would be good if he apologised."