National Party leader Simon Bridges has received a formal invitation by President of the Waikato Mongrel Mob Kingdom Chapter Sonny Fatupaito to attend their Mana Whānau event.
However, Mr Bridges rebuffed the invitation.
A letter sent on behalf of Mr Fatupaito read, "This will be the fourth kaupapa we have held this year for our people - Mana Waahine, Mana Taane, Graduation our first three, culminating with our fourth event focused on our Whānau."
It said the Kingdom Chapter was the least imprisoned chapter in Aotearoa, saying Mr Fatupaito had been driving change since 2014.
"A stark highlight of this change is reflected in the Chapter's suicide statistics having only lost two of their men to suicide in the last four years," the letter read.
The letter invited Mr Bridges to the event with the Kingdom Whānau in November, with wellbeing of family being the main focus.
Mr Bridges thanked Mr Fatupaito for the invitation, but replied: "Until you and your gang hand over your guns and stop all involvement in drugs and violence I have no interest in meeting with you."
"Gangs have been emboldened in recent times and I am deeply concerned by the swelling in gang numbers. I believe people are capable of changing and of redemption, rehabilitation and reintegration. I also believe there will be individual gang members who do good for their whānau and community.
"However, I’ve also, as a Crown prosecutor and MP, seen first hand the misery caused by gangs, particularly in their crime and peddling of drugs and violence, not least to women. These are the overriding drivers of gangs.
"Thank you for your letter and invitation but until you and your gang hand over your guns and stop all involvement in drugs and violence I have no interest in meeting with you."
Mr Bridges has been accusing the Government of being soft on crime, saying almost 1400 more people had joined gangs since October 2017.
"The latest female extension of the Mongrel Mob, gang members refusing to hand in illegal firearms and brazen gang meetings happening in public places like Te Mata Peak shows how emboldened the gangs have become," Mr Bridges said last week.
He also said criticised the lack of increase of prosecutions of gang members for methamphetamine related crimes.