Prime Minister Dr Mahathir Mohamad has refused to back down in the wake of Johor ruler Sultan Ibrahim Sultan Iskandar telling "certain parties" not to meddle in the state's affairs.

Commenting on the sultan's statement, Mahathir said if rulers had the final word on who becomes prime minister or menteri besar, then Malaysia would not be a democratic nation.

"I am of the opinion that if we assume that those who can choose the prime minister and choose our menteri besar are the kings, then we are no longer a democratic country," he told a press conference at Parliament this evening.