Williams could walk away from its Formula 1 engine deal with Mercedes as the team is in the process of assessing its options for a power unit supply for 2026.

F1 has signed off the regulations for the next generation of power units in 2026 that will see engines run on sustainable fuels and have 50% more electrical power.

While the rules are still three years away from coming into force, teams are already looking ahead to finalising engine deals.

Williams is currently a Mercedes customer team and has been powered by the German manufacturer’s power unit since 2014, but has the option to switch engine partners when the new regulations arrive.

Mercedes supplies four teams on the current grid but, unless it can get permission from the FIA, it could be obligated to drop one as manufacturers can only supply three outfits under the 2026 rules cycle.

If Williams decided to part company with Mercedes it would not be short of options, with Renault known to keen on supplying to customers and Honda mulling over a return having signalled its interest in developing a 2026 power unit.

Williams team principal James Vowles said the Grove-based squad was reviewing the options available to them but would need to make a decision before the end of the year.

“We are at the moment still in the process of making sure we understand all the options available to this team,” said Vowles, as quoted by Motorsport.com.

“The rules contain some lines which state that theoretically as taken in 2025 this is the number of teams a PU manufacturer can supply. Same rules, by the way, that should have limited [Mercedes] this year down to less PU supplies than they currently have.

“I think that’s an ongoing discussion. But no, we’re not locked into Mercedes. And we’re still in the process of reviewing.

“But we have to, as all teams will do as well, come to a decision fairly shortly. I think end of the year would be late. So a little bit before then.”

While Williams has been a Mercedes partner for the entirety of the V6 hybrid era, Vowles was clear the relationship would have no influence on what direction it decides to take.

“As you would imagine, it would be foolish to simply just go with where I’m comfortable and what I know,” he said.

“If you’re going to get your house painted, you get three quotes, I would highly recommend you do that if you don’t. And it’s the same here, I want to make sure I understand what’s available to us.”