Police will monitor the closed-door gathering reported to be attended by opposition leaders including former prime minister Tun Dr Mahathir Mohamad.

Deputy Prime Minister Datuk Seri Dr Ahmad Zahid Hamidi said the police would carry out their duties according to the standard operating procedure to monitor the gathering which is scheduled to be held in Shah Alam tomorow.

"Personally and officially, I will not interfere, like the Inspector-General of Police, Tan Sri Khalid Abu Bakar said, action will be taken according to existing laws," Zahid who is also the Home Minister, said.

He was speaking after launching and chairing the 23rd general assembly of the Malaysia Crime Prevention Foundation (MCPF) here today.

According to the social media, Dr Mahathir and former deputy prime minister Tan Sri Muhyiddin Yassin would be joining the opposition leaders in the gathering.

The gathering was seen as intending to badmouth the nation's leaders.