Amanah member Khairuddin Abu Hassan has challenged Johor crown prince Tunku Ismail Sultan Ibrahim to relinquish his claim to the throne and take part in politics.
"Your Highness, if you feel that you are great at politics and like to make political statements, I humbly advise that you relinquish your crown and enter the political arena full time.
"Your Highness should follow the praiseworthy footsteps of Tengku Razaleigh Hamzah and Tengku Azlan Sultan Abu Bakar who are involved as full-time politicians," Khairuddin said in a statement today.
He said Tunku Ismail should not hide behind royal immunity to protect himself for criticism from the public.
The Johor crown prince often makes politically flavoured remarks on social media.
Prior to voting in the 14th general election, he had made veiled swipes at Bersatu chairperson Dr Mahathir Mohamad, who is now prime minister.
He also often takes jabs at Youth and Sports Minister Syed Saddiq Syed Abdul Rahman.
Khairuddin said Tunku Ismail making political remarks can reflect badly on the royal institution.
"I am worried the people will no longer respect the palace," he said.