Red Bull Racing advisor Helmut Marko has made a surprising revelation with regards to the reason for the delay in Lewis Hamilton agreeing to a new deal with the Mercedes AMG Petronas F1 Team.

The four-time world champion is in the final year of his contract with Mercedes and is yet to agree to a new deal beyond the current campaign despite both the team and the driver being in talks since the end of last season.

Hamilton has repeatedly stated his desire to continue with the Silver Arrows team, who have been absolutely dominant in the last four years, while Toto Wolff, the Mercedes team principal, has also made it clear they want to keep the Briton in the team as long as possible.

Photo: Clive Mason/Getty Images

"We've been talking and will continue to talk,” Hamilton said, Sky Sports reported. “It's quite a relaxed atmosphere for us because Mercedes know I'm committed to them and they've obviously expressed they're committed to me.”

"Both Toto [Wolff, Mercedes Team Principal & CEO] and I sit here quite relaxed. It's about constantly trying to find common grounds. … Ultimately with contracts and partnerships you always want to work on how you can be better, provide a better service and vice versa, how you extract more from each other. So that's really what we're working on,” the Briton said.

However, despite reports prior to the start of the season suggesting a potential £120m ($167m) three-year deal was close to being concluded, there has been no progress as the second race of the season in Bahrain approaches Sunday.

Marko, who is the head of Red Bull’s driver development program, has offered a reason for contract talks between Hamilton and Mercedes stalling. The Austrian owned team’s chief has revealed Mercedes’ interest in Max Verstappen, who is arguably one of the best drivers on the grid and at 20 years old is certain to be a future world champion, and Sebastian Vettel, who is currently plying his trade with Ferrari after winning four Drivers’ championships with Red Bull.

Mercedes second driver Valtteri Bottas is out of contract at the end of the year and seems like the reigning champions could be looking for a second driver who can challenge Hamilton consistently and have thus considered Verstappen and Vettel as possible alternatives. And, according to Marko, the Silver Arrows teams approaching the two drivers has irked Hamilton and the Briton is said to have upped his asking price which has brought contract talks to a standstill at the moment.

“Toto tried to get Vettel and Max, but both declined him,” Marko told German sports magazine Sport Bild, as quoted by the Express. “Of course, Lewis heard about this so he put up his price.”

However, it will be difficult for Mercedes to prize either of those drivers from their respective teams Red Bull and Ferrari as both of them signed new long-term deals midway through the 2017 season.