Brown: McLaren "near our limit" with struggling Honda

Brown's public acknowledgment of McLaren's disappointment with the results of the Japanese marque's current work has come in the lead-up to the Canadian Grand Prix, alongside a confirmation that the first major performance upgrade for the 2017 Honda engine will not be racing in Montreal.

The McLaren-Honda partnership has so far endured a miserable start to the F1 2017 campaign, as the new Honda power unit has struggled for performance and reliability. McLaren has not finished in the top 10 in any of the first six races of the campaign, marking its worst start to an F1 season since the team's inception.

Speaking to Reuters, Brown said: "The executive committee have now given us our marching orders. We're not going to go into another year like this, in hope.

"I don't want to get into what our options are. Our preference is to win the world championship with Honda. But at some point you need to make a decision as to whether that's achievable. And we have serious concerns.

"Missing upgrades, and upgrades not delivering to the level we were told they were going to, you can only take that so long. And we're near our limit."

McLaren has spent much of the past three seasons at or near the back of the F1 pecking order since the renewal of its historic partnership with Honda in 2015, and Brown has given a clear indication the British team couldn't afford to wait much longer.

"So far it hasn't worked. A year in Formula 1 is an eternity. Three years is a decade. And you can't just go on forever."

Earlier in the year, McLaren was understood to have had a preliminary discussion with its former engine supplier Mercedes.

Brown, who had previously ruled out McLaren producing its own engines, said he believed a customer team could win in F1.

He also insisted the "commercial benefits" of the Honda contract were counterbalanced by the loss of FOM payments stemming from the team's poor position in the constructors' championship.

Having exclusively supplied McLaren over the past three seasons, Honda finalised a deal in April to provide its engines to Sauber for 2018.

The upgrade quandary

The airing of McLaren's frustrations with Honda has come alongside Brown confirming that the Japanese engine manufacturer would not have its first major performance upgrade of the season ready in time for Canada.

Honda had admitted earlier it was "very tight" on having the upgrade ready for Montreal, and McLaren's prospects for the power-sensitive layout of the Circuit Gilles Villeneuve will now be significantly bleaker.

"Honda's working very hard but they seem a bit lost," Brown said.

"We were only told recently that we wouldn't have the upgrade coming, and we don't have a definitive timeline, which is concerning because the pain is great and we can't sit around forever.

"We were eagerly awaiting this upgrade, as were our drivers, and it's a big disappointment that it's not coming.

"It's not lack of effort, but they [Honda] are struggling to get it to come together."