Khairy Jamaluddin has blamed Umno president Ahmad Zahid Hamidi for Mustapa Mohamed’s resignation from the party.

The former Umno Youth chief said that as a result of Mustapa's exit, the party had lost a “leading light.”

“I have been vocal in cautioning my party against this alliance with PAS. And I bore the brunt of attacks from within.

“Now, we have lost a leading light of our party. A brilliant and good man. This is on you, Mr President,” he said on Twitter today, as news broke of Mustapa’s resignation.

Mustapa, who was voted into the Umno supreme council with the largest share of votes in the June party election, announced his resignation tonight.

Read more: Ex-minister Mustapa Mohamed quits Umno

In his announcement, he said he wanted Umno to be more inclusive and moderate, but that this did not seem to be the path the party was taking.

"Considering this, after self-reflection and deep thought, I have taken the decision to resign as an Umno member after more than 40 years of serving the party," he said, adding that the task of addressing Umno’s trust deficit has become increasingly difficult.

Umno and PAS had been flirting with the idea of cooperation for months, including campaigning for each other in recent by-elections.

Last week, Zahid led a delegation of top Umno leaders to attend the PAS muktamar in Kuala Terengganu.

However, the Umno president later told reporters that more discussions are needed before a formal coalition could be formed.

I have been vocal in cautioning my party against this alliance with PAS. And I bore the brunt of attacks from within. Now, we have lost a leading light of our party. A brilliant and good man. This is on you, Mr Presiden.

— Khairy Jamaluddin (@Khairykj) September 18, 2018