Bridges described the firearms ban and buyback scheme as a "quiet fiasco" and suggested the Government is influencing the police to prioritise it over issues he feels are more pressing, like gang violence.

"I do - and I don't want to get into conspiracy theories - worry about the politicisation of the police," Bridges said. "I think they have to be scrupulously independent."

The National Party leader said he's seen top police officers having coffee with ministers in the Beehive in Wellington and said it "worries" him.

Williams asked Bridges if Judith Collins did the same thing when she was Police Minister under the former National-led Government.

"I don't know," Bridges replied, "but I'll tell you what I do think: we need to be scrupulous in guarding against that and ensuring that there is a separation.

"To the police, I say quite clearly: Mike Bush, you guard against politicisation of your force. It's too precious to do otherwise."

Police Commissioner Mike Bush responded by pushing back against Bridges' claims.