Former prime minister Tun Dr Mahathir Mohamad today lashed out at critics, saying he has no problems cooperating with Datuk Seri Anwar Ibrahim, just like he had done with DAP Parliamentary Leader Lim Kit Siang.

At the same time, the veteran politician stressed, nothing regarding the cooperation between Parti Keadilan Rakyat (PKR) with Parti Pribumi Bersatu Malaysia (PPBM) was brought up during his meeting with the former opposition leader at the KL courts last Monday.

"I did not discuss it (cooperation), but if I can cooperate with Kit Siang, why can't I do the same with Anwar?" he told reporters after receiving the registration approval for PPBM at the Registrar of Societies headquarters here.

Dr Mahathir also expressed hope that all opposition parties, including PAS, would create an alliance to ensure victory in the 14th General Elections (GE14).

He said, opposition parties that insist on standing along would actually be doing Barisan Nasional (BN) a favour. This was because an alliance between all opposition parties would help prevent three-cornered fights during the elections.

"If we are serious in wanting to change the government and establish a new leadership in our country, we need to work closely and effectively with each other so that we won't be weak.

"If we contest separately and not as a coalition, we are actually fighting for BN because when there is a three-cornered fight, BN will usually win," he explained.

"Based on my past experience, if opposition parties or parties that oppose the government do not cooperate with each other, they will be lose during the elections just like what has happened for the past 59 years," he said.

On Monday, Dr Mahathir turned up at the KL High Court to attend the hearing of an application filed by Anwar to challenge the National Security Council (NSC) Act 2016.

It was the first meeting between the two former UMNO leaders in 18 years.

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Commenting on PPBM, Dr Mahathir said, the party's first Annual General Meeting (AGM) would be held next year.

"There's not much time left this year and we are required to hold the party's AGM during the financial year.

"We will hold the AGM next year to determine several party objectives including party leaders," he said.