Red Bull team principal Christian Horner says Sergio Perez’s current run of F1 form is “unsustainable” as speculation over his future continues to mount.

Perez endured his latest torrid weekend at the British Grand Prix, suffering a Q1 elimination before going on to finish Sunday’s race in a lowly 17th after an early gamble on intermediate tyres backfired.

After starting the season with three second places from the opening four rounds, Perez has not stood on the podium since the Chinese Grand Prix in April, while he has finished no higher than seventh in the last six races amid a run of qualifying struggles.

The Mexican has slipped to sixth in the drivers’ championship and is a whopping 137 points behind Red Bull teammate Max Verstappen, who has largely been responsible for maintaining the team’s lead in the constructors’ standings.

“He knows it’s unsustainable to not be scoring points,” Horner admitted after Sunday’s British Grand Prix.

“We have to be scoring points in that car and he knows that. He knows his role and his target, so nobody is more eager than Checo to find his form again.”

There are growing rumours that Perez’s new two-year contract, signed only last month, contains a performance-related clause that could result in him being dropped, possibly during the current season, if he fails to turn things around.

Autosport report that Red Bull have “the right to terminate Perez’s contract if he falls more than 100 points behind Verstappen at key points of the championship – which are the summer break and the end of the season”.

Red Bull could turn to one of RB pair Daniel Ricciardo or Yuki Tsunoda, or reserve driver Liam Lawson, who is driving the team’s current RB20 car at Silverstone on Thursday.

Lawson’s filming day outing has only fuelled speculation about Perez’s future but Horner moved to downplay the significance of the test.

“The Liam aero run has been planned for a couple of months now and for Checo, of course, he’s under pressure. That’s normal in Formula 1,” Horner said.

“And when you’re under-delivering, that pressure only mounts. He’s aware of that, he knows that and this weekend nothing has gone his way.”