Tourism and Culture Minister Nazri Abdul Aziz has criticised the police's decision to bar a debate between him and former premier Dr Mahathir Mohamad.

He vowed to be present at Maktab Rendah Sains Mara (MRSM) in Kuala Kangsar this Saturday, where the debate is to be held.

"Since when did this become a police state? Since when can individual rights be blocked by others if they did nothing wrong.

"This is not a police state, this is Malaysia.

"I will be there on the 25th (Saturday), I don't want this to be a police state," he told reporters when met at the Parliament lobby today.

Police today rejected the application for the debate to be held, citing failures to comply with the Peaceful Assembly Act (PAA) by organising it at a school, as well as failing to give authorities a notice 10 days in advance.

The police also said that they had received objections from stakeholders.

Nazri, however, said he had received permission from MRSM to hold the debate.

He also said that this was a debate, not an assembly, thus did not fall under the PAA.

He also expressed disappointment that police would deny him and Mahathir a right to debate because there were some objections.

"If you want to listen to NGOs and place their rights above ours, that is not right.

"It is as though I am a communist, a terrorist. I am a minister and Mahathir is a former prime minister," he said.

Nazri added that he was not going to be boxing with Mahathir, neither would they be inciting any violence.

He assured that he would be on his best behaviour.

"I promise I will not be rude. He (Mahathir) was my old boss and he is older than me.

"I give police my assurance that there won't be any shouting, I will ensure the dialogue goes well," he said.

The Home Ministry had previously given its green light to the debate, with Deputy Home Minister Nur Jazlan Mohamed saying they had received an application from the organisers to hold the debate and will approve it.

The topics to be raised during the debate include 1MDB, the RM2.6 billion in Prime Minister Najib Abdul Razak's accounts and the BMF scandal, which occurred during Mahathir's premiership.