UMNO views Tun Dr Mahathir Mohamad and Tan Sri Muhyiddin Yassin's decision to work with the Opposition as a very big mistake, said Datuk Seri Najib Razak.

The Prime Minister and UMNO president said the action of both the former senior leaders of UMNO had also incurred the wrath and disappointment of UMNO leaders and members.

"I see most of the UMNO leaders, they are very angry and disappointed with Tun Dr Mahathir's decision to work with the Opposition.

"In fact, excerpts of Tun Dr Mahathir's speeches have gone viral, also condemnation of Lim Kit Siang as a racist leader and a DAP chauvinist.

"Tan Sri Muhyiddin and Tun Dr Mahathir have previously condemned and criticised Kit Siang and DAP outright. Which is why UMNO leaders cannot accept (this). They know what DAP's stand is all this while, so what they did is a very big mistake," he told reporters here today.

Najib said this in commenting on the action of the two leaders in joining forces with the Opposition at a ceremony to come out with the Citizens' Declaration in the federal capital on Friday (March 4).

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At the event, Muhyiddin and also former menteri besar of Kedah Datuk Seri Mukhriz Mahathir were among 50 individuals who signed the declaration which was led by Dr Mahathir, who quit UMNO recently.

Also supporting the declaration were Lim, who is DAP advisor, Selangor Menteri Besar and PKR deputy president Datuk Seri Mohamed Azmin Ali and former MCA president Tun Dr Ling Liong Sik.

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Asked if action would be taken against the UMNO leaders involved, Najib said: "It is up to UMNO's Supreme Council and Disciplinary Committee.

"We, each leader at whatever level, is subject to the constitution and disciplinary requirements of the party."

Asked if this was a final warning for Muhyiddin, he said: "Let MT (UMNO's Supreme Council) decide. We believe the highest body is the supreme council."

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On Kedah UMNO Liaison's decision that action be taken against Muhyiddin and Mukhriz, Najib said he did not want to make the decision alone and was leaving it to the MT.

"I leave it to the MT. I do not want to make a decision by myself. We practise collective responsibility," said the Prime Minister.

Despite all this, Najib said the government will concentrate on the country's development as well as serving the rakyat (people).

"As far as we are concerned, the confidence level depends on elections. At the moment, the government will continue because we have the mandate and numbers in Parliament. The party is also behind the government," he said when asked whether he was confident that the people were still with UMNO.

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Earlier, Najib, who is on a one-day working visit to Johor Bahru, had launched the Urban Transformation Centre at Galleria@Kotaraya here.