Mark Webber thinks Ferrari should consider writing off the 2019 world championship after the next race in Canada.

So far this year, Mercedes has scored five consecutive 1-2 finishes, and the dominant German team looks set to keep dominating in Monaco.

"If it keeps going on for months then at some point Ferrari needs to focus on 2020," Webber told Sky Italia.

"If they're still chasing after Canada, then they have a real problem," said the Australian.

"Mercedes is just so well organised, especially on the race days. They seem confident and relaxed and they're impeccable every time, even under great pressure," Webber added.

"Regrettably, for Ferrari, Mercedes seems to have succeeded in achieving excellent aerodynamic balance with a car that is fast on every type of race track," said the former F1 driver.

As for Ferrari, Webber said: "They give the impression of disorganisation. They are not pro-active, but rather they always seem to be reacting to something that is happening."

Webber knows Ferrari's number 1 Sebastian Vettel well, having raced alongside the German at Red Bull.

"I see two problems with him," Webber said.

"Not only is his car not competitive enough, he also has a damn fast teammate. Even if Seb had a really good car, he would have to share the victories to Leclerc.

"But with Ferrari not winning at all, it builds up the pressure more and more while Leclerc can just keep pushing. I think Seb is strong enough to respond, but he'll need a lot of support from Ferrari for that."