Honda on Monday accused MotoGP leader Valentino Rossi of deliberately making Marc Marquez crash in Malaysia in a claim that ratchets up the tension ahead of this weekend's title showdown in Valencia.

Rossi leads the 2015 championship by seven points from Jorge Lorenzo but must start from the back of the grid on Sunday after stewards in Sepang found him guilty of kicking Honda star Marquez off his bike.

Rossi is appealing the punishment with a hearing set to take place 48 hours before the race.