Tun Dr Mahathir Mohamad needs to announce who he wants to be Prime Minister and Deputy Prime Minister, if the former prime minister intends to stop speculation that he is paving the way for his son Datuk Seri Mukhriz, said Press Secretary to the Prime Minister Datuk Seri Tengku Sariffuddin Tengku Ahmad.

Tengku Sariffuddin said if Dr Mahathir wants his attempt to unseat the Prime Minister Datuk Seri Najib Razak to have any credibility, he must at least give a straight answer on who the alternative candidate is.

"Whydoes he (Mahathir) always avoidanswering this one simple but essential question? Why is he consistently evasive about his plans for Datuk Seri Mukhriz's political future?

"If he still refuses (to name the alternative candidate), he should stop this distraction for Malaysia and quietly retire with thegracepeople expect of a former statesman," Tengku Sariffuddin said in a statement Saturday.

Yesterday, Mukhriz was reported as saying that he will sue Tengku Sarifuddin if he did not retract his comments about Dr Mahathir promising Tan Sri Muhyiddin Yassin the post of Prime Minister, with the understanding that he grooms Mukhriz to succeed him. Tengku Sarifuddin said it is the people, not one man, who under the constitution are entitled to democratically choose their government and prime minister in the next general election.

On Mukhriz's statement where he told a foreign newspaper yesterday that he had no ambition to be Prime Minister, Tengku Sariffuddin then raised a question on why the ex-Kedah Menteri Besar contested the UMNO Vice President post in 2013.

Tengku Sarifuddin said, everyone in Malaysian politics knows that only someone who wants to be UMNO president, and then by default Prime Minister, would stand to be Vice President as it is a key step on the ladder to the top.

"Maybe it's because he lost the contest that Datuk Seri Mukhriz contradicts himself by saying he didn't want to climb the ladder.

"Or maybe because he was told to say this by his father, Tun Dr Mahathir Mohamad. But we all know that he or his father did want him to climb the ladder, because he stood for election as Vice President," added Tengku Sarifuddin.