Eddie Irvine says Lewis Hamilton 'lost the plot' when he went 'too showbiz'

Hamilton's solitary victory in 2013 occurred at the Hungarian GP

The 28-year-old burst onto the scene in 2007, finishing second in the standings and ahead of reigning champion and McLaren team-mate Fernando Alonso, before securing the drivers' crown the following season.

Since then, however, Hamilton has failed to mount a sustained title challenge, never finishing higher than fourth in the Drivers' Championship.

Irvine, who narrowly missed out on the 1999 title, feels Hamilton has been distracted by matters off the track, but still thinks the Mercedes driver can be the man to end Sebastian Vettel's domination.

"I think Lewis lost the plot a little bit because he went too showbiz," he told the Belfast Telegraph.

"His entry into Formula 1 was fantastic and his talent was amazing. Then he wanted to be a movie star or a rapper or something else. People want their sports stars to be 100% committed to being sports stars.

"I think he is coming back from that now and it would be nice if he could challenge Vettel. Lewis and Fernando Alonso are the two guys capable of taking Vettel on if their cars are up to it. Unfortunately, they aren't at the moment."

Vettel's current period of domination has been compared with that of fellow German Michael Schumacher's at the turn of the century. Irvine, who was team-mates with Schumacher at Ferrari for four years, doesn't think they can be compared, however, as the seven-time World Champion moved teams from Benetton and "rebuilt Ferrari".

"Vettel's record is amazing, though he has kept the best car pretty much every year which Michael didn't have," the Ulsterman added.

"The one thing about Michael was when he won his first two championships he felt, 'This is boring, I'm going to go to Ferrari and re-build Ferrari' and that was very admirable. He struggled there for four years before he won another championship.

"Vettel just staying at Red Bull winning trophies is boring. I don't see what he's trying to prove. Okay, he's going to collect a lot of championships, but you know what, who cares?"

Now 48, Irvine revealed he doesn't keep close contact with any of the drivers, even if Kimi Raikkonen does occasionally call him.

"Not really. I pretty much do my own thing," he revealed. "I don't really keep in touch with anyone. Kimi Raikkonen rings me the odd time when he's drunk!"