Toto Wolff insists Lewis Hamilton is still capable of winning an eighth Formula 1 title.

"Clearly yes, and I emphasise that strongly," said the Mercedes boss, following recent reports and opinions questioning the ability of the now 39-year-old to return to top winning form.

"There is a reason why Lewis has broken all records and won seven world championships - because his skill is on a higher level. If we give him a good car that he can trust, he can get back in front of everyone," Wolff added.

In a recent interview, however, Hamilton had admitted that he sometimes doubts his abilities.

"All the extraordinary people I met in my life are like that," Wolff told La Gazzetta dello Sport.

His comments come amid Mercedes' announcement of a new long-term contract for returning technical director James Allison, with Wolff describing him as "the most impressive technical leader in our sport".

Allison's task is to end Mercedes' recent losing streak and overtake Red Bull.

"Catching up isn't quite as nice as winning," Allison is quoted as saying by Auto Motor und Sport, "but it's inevitable in sport. You have to stand up when you haven't done your job well enough.

"Red Bull was in no man's land for years," he added. "They can now be even more happy about their success. We want to go there again."

However, Allison admits that beating Red Bull as soon as 2024 may be difficult, agreeing with Hamilton that it will be like climbing Mount Everest.

"It is the most difficult task imaginable," he said, "but it is possible."

He said early simulator tests of the new car show that "the rear is more stable" and "the road holding is more balanced".

"Last year we analysed our weaknesses, hypothesised the reasons for them and are now curious to see whether our actions confirm the diagnosis and hypotheses."