Families of victims gunned down at two New Zealand mosques urged a judge to impose the toughest possible sentence, life without parole, on the gunman as he showed no remorse and appeared to smirk at one survivor during a sentencing hearing yesterday.

Mirwais Waziri, who was wounded during the 2019 attack at Christchurch's Al Noor mosque, put aside his prepared court statement and addressed white supremacist Brenton Tarrant directly, after seeing that he did not have "any regrets".

"He does not regret anything," said Waziri in the High Court in Christchurch on day two of the sentencing hearings.

"Today you are called terrorist and you proved to the world that us Muslims are not terrorists. I say to the people of New Zealand that terrorist do not have religion, race and colour," said Waziri," whose words drew applause from the public gallery.

Nathan Smith, originally from Britain and a survivor of the Al Noor mosque shooting, also spoke directly to Tarrant who sat in grey prison clothes cornered by guards.

"When you get a free minute, which you will have plenty of. Maybe you should try to read the Quran. It's beautiful," he said, reacting to Tarrant's apparent smirk.

Tarrant, a 29-year-old Australian, is scheduled to be sentenced this week after pleading guilty to 51 murders, 40 attempted murders and one charge of committing a terrorist act during the 2019 shooting rampage in the city of Christchurch which he livestreamed on Facebook.

Prosecutors have told the court Tarrant carefully planned the attacks to cause maximum carnage by accumulating high-powered firearms and ammunition, training at rifle clubs and studying mosque layouts.

A murder conviction carries a mandatory sentence of life in prison. The judge can impose a life term without parole, a sentence that has never been used in New Zealand.