Mukhriz Mahathir argued that his father, former premier Dr Mahathir Mohamad, would have helped elevate his political career when he was prime minister, and not 13 years after his retirement.
The former Kedah menteri besar was responding to the allegations by Prime Minister Najib Abdul Razak’s press aide Tengku Sariffuddin Tengku Ahmad, which Mukhriz described as baseless.
Mukhriz has also sued Tengku Sariffuddin for defamation.
"If Mahathir wanted to appoint me or assist me in my political career, he would have done so when he was still prime minister and party president for 22 years.
"It is illogical for Mahathir to have the intention to do so after retiring from politics and after leaving the highest post in the country and party for 13 years," he said in a statement.
"There is no basis in Tengku Sariffuddin's allegation that I contested the post of party vice-president to fulfill my ambition to be the party president and prime minister.
"It is common knowledge there are three vice-presidents and the posts of deputy president and president are elected...This shows that the process from being a vice-president to president is not easy and automatic," he added.
He also refuted Tengku Sariffuddin's statement that securing the Umno president's post would ensure the post of prime minister as well.
"This shows Najib's press secretary has a shallow understanding of the Federal Constitution as it is the MP who gains the support of the majority in the Dewan Rakyat who can become the prime minister. There is no guarantee that it is exclusive to the Umno president although the past six prime ministers were also Umno presidents," he said.
"I deny that all my political actions, including offering myself (as a candidate) in the Umno election were aimed at becoming Umno president and eventually prime minister.
"I strongly deny the allegations made by Tengku Sarifuddin which have no basis, as there is no conspiracy involving me to overthrow Najib, have (former deputy premier) Muhyiddin (Yassin) become prime minister and for Muhyiddin to guide me to replace him to that post (later)," he added.
Mukhriz accused the prime minister's aide of attempting to deflect the people's attention from the 1MDB and SRC International issues.
The former Kedah menteri besar argued that the people would not be duped, and vowed not to allow those responsible for such "dirty tactics" to evade action.
He also believes that through the Citizens’ Declaration, the people are becoming braver in their quest to save Malaysia.
"I am with the people to ask Najib to step down as prime minister," he added.
In his lawsuit, Muhriz had cited four media statements issued by Tengku Sariffuddin between April 15 and April 26, which he claimed painted a picture of him being power crazy, immoral and unprincipled.
He also said the media statements accused him of conspiring with his father and Muhyiddin to bring down a lawfully elected government and seize power for themselves.
