With Spaniard Alonso now on the driver market for 2018, some have linked him with a move to Mercedes.
That would reunite the old Alonso-Hamilton partnership of 2007, with Alonso always saying he only clashed with McLaren's culture and supremo Ron Dennis.
But when asked if he would want to be paired with Alonso again, Hamilton told Spain's El Pais: "It's not just about me, but the hundreds of people working in the team.
"My relationship with Fernando was toxic and it intoxicated the whole team.
"So yes it was personal. There are people with whom you get along and others who you cannot coexist with in any way," said Hamilton.
"If you put two world champions in the same team, each will try to do his best and neither will give way on a single corner. There is too much friction."
But the Briton said that in the years since the "toxic" McLaren season, he actually now gets along with Alonso.
"Formula one is a show and there are very few drivers who are able to make it that show," said Hamilton.
"There's Alonso, Vettel, myself ... So I hope they (McLaren) can solve the problems he is having with his team."
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