Max Verstappen has threatened to quit Formula 1 at the end of this season if planned changes to the engine regulations for next year are blocked.

Governing body the FIA said two weeks ago that an agreement had been reached in principle to changes that would reduce the need for energy management with the new engines introduced this year.

But opposition has emerged in subsequent talks around the detail of the plan and there is currently not enough support for the move to be passed under F1's governance protocols.

"If it stays like this, it's going to be a long year next year, which I don't want," said Verstappen.

"It's just mentally not doable for me to stay like this. It's really not."

Verstappen confirmed that if he did decide to stop, he would not come back. "There's a lot of other fun things out there," he said.

Drivers have been complaining this year about the way the new engines, which have a nominal 50-50 split between internal combustion and electrical energy, have reduced their ability to drive on the limit at all times.

The engines are energy starved, which has required techniques to recover energy even on qualifying laps.

One change has already been made to address this and the latest plan is to make the energy split - which is actually currently about 54-46 in favour of the internal combustion engine - 60-40.

The effect of this will further reduce the need for energy management, especially in qualifying.

Verstappen said on Thursday that the planned changes would return racing "almost back to normal" - and hinted he would stay in the sport as a result.

"It will make the product better, so that means that I'm happier," he said. "And that's what I want. To be able to continue and perform well.

"For me, I'm happy where I'm at. I see the team really progressing. And that's also very exciting to see."

However, while Mercedes and Red Bull are in favour of the change, other manufacturers are opposed.

Audi has issues with cost and Ferrari are said to be concerned about losing out on the extra development opportunities they expect to be permitted after this race under F1's rules.

Talks have been ongoing over the Canadian Grand Prix weekend and there is still optimism that sufficient manufacturers opposing the change can be persuaded to change their minds for the move to be voted through.

Verstappen, who said after the Japanese Grand Prix that he was considering his future as a result of the new engine rules, added after Saturday's qualifying session in Canada: "Let's stay on the positive side - we're still, I think, looking towards making those changes.

"Of course some people at the moment that maybe have a bit of an advantage will try to be difficult about it, but if the FIA is strong, and also from the F1 side, they just need to do it."

McLaren team principal Andrea Stella said: "The proposal that was put forward by the FIA looks at increasing the ICE power through the fuel flow, looks at redistributing the electrical power in harvesting, in deployment, the battery capacity. They were all part of a very important package that will make Formula 1 better.

"And this is a general interest that should prevail over the particular interests. Because if we don't have a good sport, if we don't preserve the value of the business, the value of Formula 1, everyone will have a loss.

"This will overcome finally some of the limitations that are fundamentally inherent to this hardware that we are using at the moment."

The current rules have encouraged an unusual style of driving where often delaying throttle use out of a corner leads to a faster lap time because the car then has more electrical energy for use on the straight.

Stella said: "If I listen to the debrief, once again the drivers said 'I did such a good job in going on power so early out of corner seven, and so early out of corner nine, I'm gaining on the exit a little bit and then the other car gains because he was slower going on power and now he has more deployment'.

"This is something that we want to cure, and we have a possibility to do it in 2027."