Michael Schumacher has not been good for Formula One, his former rival Damon Hill has told BBC Radio's Today show.
Schumacher pipped Hill to the 1994 world title
The 1996 world champion, who had several run-ins with Schumacher, said: "Brilliant driver though he is, I think he has not been good for the sport."
Hill was glad to have raced Schumacher because it had pushed him to levels "I never thought I would achieve".
But he added: "From time to time the entertainment value has waned slightly with Michael's dominance."
Hill believes that Schumacher has the edge in his battle with Fernando Alonso for the 2006 title, which the German could clinch in Japan this weekend.
"I have to say that psychologically Michael is bullet-proof," he said.
Michael's a very tough competitor
"Alonso has made some remarks recently about not having the support of the Renault team, which were ill-judged and show some sort of weakness there really.
"Alonso has poured his heart out to a journalist and it looks like he is feeling the pressure, which is one up to Michael again."
Hill's most notorious run-in with Schumacher came in 1994 at the season-ending Australian Grand Prix in Adelaide.
Schumacher led the championship by a point going into the race, during which the pair collided after the German turned his Benetton into Hill's Williams.
Neither could finish and so Schumacher won the title.
"I don't think it's a question of forgiving. It was all very exciting at the time and you just try to get stuck into the next season," said Hill.
"It was disappointing that I didn't win but, to be fair, it was a closely-fought championship and a bit of an unusual one and a sad one because we lost Ayrton Senna. So quite honestly I was glad to see the back of it.
"Michael has done some amazing things, there's no question. I would not take away any of my opportunities to race against Michael Schumacher because he drew out of me a level of driving that I never thought I would achieve. He's a very tough competitor."
He added: I'm looking forward to F1 without Michael and hoping that we will see some real competition again between drivers within teams as well as drivers against each other in other teams."