Honda-powered McLaren has not won a Grand Prix since 2012 while Mercedes, with triple champion Lewis Hamilton and Nico Rosberg, have been victorious 36 of 43 since the start of the V6 turbo hybrid era.
This weekend's showcase Monaco Grand Prix has been won by championship leader Rosberg for the past three years, although McLaren is historically the most successful team in the principality with 15 wins.
“I honestly believe that the next world champion after Mercedes will be McLaren,” Dennis said. “We'll get to that goal before other people.
“It is challenging but I have a firm belief in the technical competence of our people and a firm belief in Honda.”
Also read: Can Rosberg match Senna's Monaco record?
Former champion McLaren, the most successful team after Ferrari in the history of the sport, has scored 12 points from five races this season compared to Mercedes' tally of 157. Ferrari is second with 109 and Red Bull third on 94.
Honda returned in 2015 as McLaren's partner but was plagued by unreliability and a lack of power.
This year has seen improvement, with Jenson Button scoring in the past two races and Fernando Alonso sixth in Russia and reaching the final phase of qualifying in Spain.
Dennis said the 2017 rules revamp represented an opportunity.
“The 2017 regulations level the playing field and it is enough time for us to catch up with Honda, so I think we'll have a good chance next year,” he said.
New Renault engine
Renault, which powers Red Bull - although the units are badged as Tag Heuer - expect a big step up after testing its new engine last week.
Renault F1 operations director Remi Taffin predicted a gain of about half a second a lap and said the new unit could be taken to Monaco.
“We had originally planned to use the new version in Canada when the current units are scheduled to be removed from the cycle, but if we can get the units together and completely validated by Monaco we will use the ones available at this race,” he said.
Red Bull won in Spain with 18-year-old Dutch driver Max Verstappen, the sport's youngest winner.
Ferrari has also closed the gap on Mercedes since 2015, and believes it should have won already this year with more luck and reliability.
Like us on Facebook
Follow us on Twitter
Subscribe to our Newsletter
Original source: McLaren reckons it’ll topple Mercedes