McLaren looks set to be denied Formula 1 engine options from Mercedes and Ferrari for 2018 as it considers its options for next year's supply, as hinted by executive director Zak Brown.

Currently sat at the foot of the F1 constructors' championship thanks to ongoing issues for engine partner Honda, McLaren is known to be considering a break with the Japanese manufacturer for 2018 in a bid to move up the grid.

A return to Mercedes power had been mooted, while speculation arose across the British Grand Prix weekend that a Ferrari deal could also be possible.

Speaking to Sky Sports at Silverstone, Brown hinted that help from the likes of Mercedes and Ferrari was unlikely, saying that McLaren's rivals are taking some pleasure in its ongoing struggles.

"This whole Formula 1 is one big movie with lots of different episodes along the way," Brown said.

"We're a big team that knows how to win races and championships. I think most of the teams, while it's a shame to see us where we are, they like us where we are.

"They don't want to get us too close to them which is understandable. We're working through this with Honda every day is a new day."

Star driver Fernando Alonso has urged McLaren to make a quick decision on its engine deal for next year in order to aid its preparations, and Brown confirmed that a final call would have to be made in the coming weeks.

"Our 2018 car, we're starting to work on now, and you can only go so far before you need to know the architecture of what you're doing," Brown said.

"I think around the summer time, before or after, which obviously isn't far away, we need to finalise what we're doing with Honda moving forward.

"We can't continue to be uncompetitive. That's not what McLaren race for, it's been three years. We need to see some dramatic power adjustments or some different ways to get there.

"Like Fernando, we want to be winning races and be on the podium, and in the current state we are, we can't, so some things need to change."