Are Williams about to become Mercedes' B team?

Williams may become more closely aligned with Mercedes in 2019 as they ponder adding gearboxes to their power unit order from the Silver Arrows. The move may be of interest to other midfield teams as the thorny issues of 'B' teams in Formula 1 swirls around the matter of Force India's future in particular.

Williams are among a clutch of teams - including McLaren and Renault - who have hesitated on signing off a rescue package for Force India over fears that they could become a "slave" team, in Cyril Abiteboul's terms.

Force India already take gearboxes as well as power units from Mercedes, so Silver Arrows team boss Toto Wolff does not envisage it causing too many issues.

"We are in discussions about doing that," he said. "They are an engine client of ours. It's not a huge thing to increase that to a gearbox.

"Nothing is signed, nothing is done and we need to decide in the next few weeks because the chassis design is at an advanced stage for Williams, so we'll see how that pans out."

Although Williams have previously boasted about their independent nature in F1, this move is another sign of F1 becoming dominated by engine manufacturers, with Haas among the strongest midfield teams thanks to an agreement with Ferrari which sees them take the maximum amount of parts from Maranello.

Williams chief technical officer Paddy Lowe told F1's official site: "Formula 1 is changing. Force India were one of the early ones to abandon the full constructor definition that teams had historically followed of essentially making everything except an engine.

"We've seen more and more teams adopting gearboxes from elsewhere. Now we have the Haas model where you adopt everything that is not listed.

"We have our eyes open to all of those possibilities because we owe it to ourselves. You've got to move with the times and do the best thing for the performance of the team.

"But having said that, Williams has a strong culture of being an independent, being a constructor, not only in the parts we are responsible for but also we are making them in-house.

"We have a capacity of manufacturing on our own site and we've prided ourselves on that. I don't see us moving drastically away from that. But we remain open."