Lando Norris has "emerged from the pack" to represent the main threat to Red Bull, says the team's principal Christian Horner.

Alongside reigning champion Max Verstappen, Norris has finished in the top two positions at five of the last six races, including Sunday's Spanish Grand Prix.

The McLaren driver has also finished in the top four in each of his last six races, as many times as in his previous 15.

He has led for a career-high 58 laps this season and his next podium finish will see him match John Watson for 13th place in the charts for all British drivers, with 20.

Looking back on last week's race in Barcelona, Horner acknowledged Verstappen – who triumphed by 2.219 seconds – was fortunate to make a strong start count.

"If Lando had track position it would have been difficult to beat him," Horner told Sky Sports News.

"It was so close between the two of them and they were 18 seconds ahead of the rest. I would say Lando has emerged from the pack as the most consistent challenger.

"We've had four pole winners in the last four races. It's very, very tight.

"But Lando I would say, he seems to have worked out these tyres, McLaren have done a great job as well, and they're going to push us hard for the rest of the year."

Red Bull are on home turf this weekend at the Austrian Grand Prix, for the third sprint race weekend of the season.

"On such a short lap, it's going to be so tight and we expect McLaren and Lando to be fast again," Horner added.

"Ferrari and Mercedes? Who knows. If you look at the gap to those guys after the race it was pretty similar to last year. The one who has stepped up is Lando."