McLaren Formula 1 boss Zak Brown says he is "surprised" to find the team in a battle with Red Bull for the world championship this season.

McLaren trail Red Bull by just 42 points in the constructors' championship as the season heads into its final 10 races.

"If I were to sit here and say I'm not surprised, that would be disingenuous," Brown told BBC Sport in an exclusive interview.

"Red Bull had such an advantage over everyone and Mercedes has been so dominant.

"I felt like we'd continue to close the gap. Did I think we would be here at the summer break, one race away from getting the lead?

"That race would have to be first and second and fastest lap, and do I think it's going to happen like that? No. But if we keep the same trajectory we've been on the last six, seven races, we'll be where we need to be by the end of the year.

"I thought we might get where we are now by 2025. I didn't think we would be where we are now in 2024. But I'm not complaining."

McLaren were 115 points behind Red Bull after the sixth race of the season, the Miami Grand Prix, where their driver Lando Norris took his maiden victory.

At least one McLaren driver has been on the podium at every one of the eight races since then, Norris' team-mate Oscar Piastri has also taken his first grand prix win, and Red Bull's form has slipped after a dominant start to the season.

But Brown suspects the constructors' race will run all season - and says it's hard to predict because of the form of Red Bull's Sergio Perez, whose recent slump is partially responsible for the closing gap. Perez has not finished higher than seventh since Miami.

"It's going to be tough," Brown says. "I think it's going to come down to the last race. There's not much between the cars. It's gonna come down to how does Sergio Perez perform?

"If he can perform as he's capable of performing, it's going to be a hard fight. If he continues to perform as he has this year, we have a pretty good chance, because we have two drivers constantly performing at the front."

In the drivers' championship McLaren are also second, but winning that is a tougher task - Norris is 78 points behind Red Bull's Max Verstappen, an imposing advantage when the Dutchman performs at such a consistently high level.

McLaren and Norris could be in an even better position had the team and driver not made a handful of small but key errors.

Norris' slips have often come at starts, such as in Spain, Hungary and Belgium. With the team, at Silverstone a couple of strategy choices were also costly.

But Brown, McLaren Racing's chief executive officer, says: "We've all made a variety of errors, which to me are learning experiences. I thought [Mercedes team principal] Toto [Wolff] was accurate with his comment. He said: 'Well, sometimes you figure these things out once they've kind of been put on your plate.'

"So if I look at the mistakes we've made - whether those are drivers or us, kinda doesn't matter; we're one team - we wouldn't make these mistakes again. We're learning. And I think maybe because we have got where we are quicker than we thought, it shows we still have learning to do."

Brown admits the British Grand Prix was one that got away. "We probably should have finished first and second at Silverstone," he says.

"And yeah, Lando is trying to fight for a world championship. He's going for it. He's learning, as are we. So I'm not concerned about it."

McLaren find themselves in this position because of their remarkable progress since Brown made Andrea Stella team principal in December 2022.

The move was prompted by former team principal Andreas Seidl telling Brown he would be joining Audi in 2025 in time for the start of their F1 programme.

Brown decided to expedite the process. He let Seidl go early and promoted Stella. Seidl's departure was followed by that of James Key as technical director and head of aerodynamics Tony Salter.

Since then, McLaren's turnaround has been nothing short of astonishing. They admitted they would start 2023 slowly, a legacy of design errors made in 2022, but said they could see progress was coming.

The first big upgrade to the car in mid-2023 leapt them from the lower midfield to the leading pack behind Red Bull, where they were competing with Ferrari and Mercedes for the rest of last season.

This year started with them third fastest behind Red Bull and Ferrari, but a major upgrade in Miami - on pretty much the whole of the car - put them toe-to-toe with Red Bull, and they have been there ever since.

Brown points to Stella and the changes he has made to the team's structure and operations as the main reason for this.

"He unlocked the talent that we already had here," Brown says. "We've got approximately 1,000 people here in F1. I changed three. But it was three leaders. So 997 are the same people who gave us the [uncompetitive] car at the beginning of 2023.

"A leader's job is to get the most out of their people and that's what we didn't have previously. We weren't able to let the talent we have in here flourish.

"Andrea communicates very well. He listens very well. He's very hard-working. He's very technical. He leads by example. All the traits you would want in a great leader. He unlocked the potential this team clearly had sitting there."

Stella joined McLaren in 2015 but was not promoted to team principal for another eight years. Why?

"Truth be known," Brown says, "I offered it to him the first time around [when Seidl was appointed in January 2019], and he declined it. He felt he wasn't ready.

"Andrea is someone who knows his capabilities and doesn't overreach.

"The second time around he knew me better, knew the team better, even though he'd been here a while. And still he didn't say yes in the first phone call. It took a couple of days because he's very methodical, very thoughtful."

McLaren now find themselves back in the place such a storied team expects to be - at the front. But it has been a long journey to get back here.

Until this season, the last in which they were fully competitive was 2012, when Lewis Hamilton and Jenson Button were their drivers.

After that, they started a slump that featured major management upheaval, including the ousting by the board of long-time head Ron Dennis, an F1 legend, whose visionary management changed the face of the sport from the early 1980s.

Brown says the state McLaren were in when he joined in 2016, initially as executive director, was something of a shock.

"It was worse than I thought it was," he says. "We were ninth in the championship. We had blank race cars, I think three sponsors. We had upset fans, upset racing drivers and we had a pretty down and out racing team. It was pretty scary."

Brown had previously become a millionaire running a sponsorship acquisition company. His first steps were to sort out the financial side.

"The team needed resources, because we were losing a tonne of money, to be able to invest in drivers and technology and people," he says.

Progress was steady from then on, including changing engine suppliers from Honda to Renault and then to Mercedes, until in 2022 Brown "felt like it was stalled out".

"Put Andrea in charge. He does a little bit of reorganising - a little bit more than a little - does tremendous work, rallies the team, and we've been on fire ever since. But we'll hit some speed bumps along the way."

As he's been rebuilding McLaren, Brown has not been shy to speak out on matters he believes are important outside the team. And it just so happens that a number of those have been related to Red Bull, the team McLaren are now fighting for the world title.

First, there was the row in 2022 over Red Bull's breaching of the budget cap in 2021. Brown said this "constituted cheating", much to the annoyance of Red Bull team boss Christian Horner.

And this year, Brown has joined Wolff in calling for full transparency after a female Red Bull employee accused Horner of sexual harassment and coercive, controlling behaviour. Horner has always denied the allegations and a Red Bull internal inquiry dismissed the complaint. A second inquiry, following the complainant's decision to appeal, is ongoing.

Brown says: "I've known Christian for about 25, 30 years. We used to race against each other. I would say we used to get on.

"I believe in transparency. I believe in putting your hand up when you get something wrong. The cost cap, the excuses behind that, I never really heard a 'we just got it wrong'. I heard excuses and not taking ownership.

"When someone breaches the cost cap, and doesn't seem to kind of take it seriously, that's kind of hitting the integrity and core of the sport.

"To me, it's not personal. It's protecting our sport.

"And when I see things not consistent with our values, I'm going to speak up about it because it's important people understand where we're coming from.

"I realise that's not necessarily always going to be popular, or make friends with everyone in the pit lane, but as long as I'm friends with McLaren, our fans, our partners, that's what's most important to me."

The Horner situation was a direct influence in design legend Adrian Newey's decision to negotiate an early exit from his Red Bull contract earlier this year.

Like all leading teams, McLaren considered whether to try to sign Newey, but Brown is confident enough in the strength of the team now that he says he is not going to pursue him.

"We're not going to sign Adrian," Brown says. "I'm very happy with the team. Adrian is a great friend, huge talent, resume [CV] second to none. But with what we have in place here, I couldn't be happier. We can get the job done. I'm happy with the race team we have and we're going to try to win the world championship with the team sitting here today."

Can they do it this year?

"It's gonna be a slug-fest. I think it's gonna be a slug-fest between all four teams [Red Bull, McLaren, Mercedes and Ferrari]. You're gonna see epic battles. Eight drivers that can show up at almost any track and win, and it's gonna be exciting."