Prime Minister Najib Abdul Razak has dismissed speculations regarding the appointment of his cousin Hishammuddin Hussein as a special functions minister.

He cautioned all quarters against attempting to drive a wedge between Hishammuddin and Deputy Prime Minister Ahmad Zahid Hamidi.

He also revealed it was Zahid's idea to give Hishammuddin, who is defence minister, the additional portfolio.

"I had been discussing the (special functions minister position) with Zahid for months. And then, it was Zahid who suggested that Hishammuddin be awarded the post.

"So please, do not create any friction between them," he was quoted as saying by the New Straits Times.

Najib was speaking at the launch of BN's largest election machinery, JR Plus, at the Putra World Trade Centre in Kuala Lumpur.

The prime minister also assured the audience that there was no rift between Hishammuddin and Zahid, pointing to the pair who were seated on stage.

"Look at them. There is no friction and (because of Zahid's suggestion), they are really nice and can sit next to each other.

"The only thing they haven't done is kiss each other," he joked, drawing laughter from those present.

After Najib announced Hishammuddin's appointment on Wednesday, it ignited a slew of speculations, among them was the claim that Najib is planning to sideline Zahid.

Both Hishammuddin and Zahid have dismissed the speculations.