Prost: Why Hamilton won't win 2018 F1 title

Alain Prost believes the crowded nature of the Formula 1 title picture will prevent Lewis Hamilton from winning a fifth championship in 2018. Hamilton moved to the top of the drivers' standings with victory at the Azerbaijan Grand Prix last time out, but the reigning champion has been off-colour for much of 2018.

Vettel stole victory from Hamilton in Australia and the Brit followed that with third and fourth-place finishes in Bahrain and China, but victory fell into his lap in Baku as Vettel failed in an attempt to overtake Valtteri Bottas, who then suffered a heart-breaking puncture after running through debris.

Mercees' dominance of F1 has been tested like never before in the hybrid era this year, with Ferrari arguably moving ahead of the Silver Arrows in terms of performance, with Red Bull also in the mix, giving Hamilton five potential title rivals.

Hamilton's four titles have come while generally battling a single opponent - Felipe Massa in 2008, twice Nico Rosberg and last season's tussle with Vettel - Prost says the congested nature of battle could cost the reigning champion.

"The six drivers for Mercedes, Ferrari and Red Bull can be competitive in all circumstances," Prost told Autosprint.

"It's more difficult for Hamilton, who has usually fought for championships against single drivers only.

"Now he will not be able to manage races in the same way against four or five competitors, but for us it will be exciting."

Ferrari's step forward has put Mercedes on the back foot after four years of dominance and Prost believes silverware will be returning to Maranello come the end of the year.

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"I made a mistake last year when I said that every time there is a change of regulation, Ferrari was rarely there," the four-time world champion added.

"In the winter Mercedes and Red Bull seemed to be a little better, but it turned out that they [Ferrari] are there in qualifying and tyre management. And also, [Kimi] Raikkonen is there at Vettel's level which will be a great help.

"I think this year Ferrari can win. I think the engine has progressed more than the chassis."