The suspect charged with the Christchurch mosque attack released a ‘manifesto’ before carrying out the shooting.
In the 74-page document published online, Brenton Tarrant, 28, sets out a motive that referenced a “future for white children” and “the existence of our people”.
He also referred to the Rotherham grooming scandal and to Brexit which he suggested was an attempt by Britain to “fire back at mass immigration”.
"People must face the fact that it [Brexit] wasn't a damn thing to do with the economy. That it was the British people firing back at mass immigration, cultural displacement and globalism, and that's a great and wonderful thing,” he wrote.
- Read more: 49 killed in mass shooting at New Zealand mosques
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“Many of you may already know about the rape of British women by the invading forces, Rotherham of course being the most well-known case.”
Some 49 people have been confirmed dead in the mass shooting. Tarrant has been charged with murder and is set to appear in court.
He added that the political figure he identified with most was Sir Oswald Mosley, the former leader of the British Union of Fascists.
Tarrant referenced London Mayor Sadiq Khan in his 'manifesto'
He also declared London Mayor Sadiq Khan was an “invader” whose election was an "open sign of the disenfranchisement and ethnic replacement of the British people".
"What better sign of the white rebirth than the removal of this invader?" he wrote.
MPs have since gathered in the House of Commons for a minute's silence in memory of those killed.
Speaker John Bercow led tributes to the victims, telling the chamber the pause in proceedings at 11am was in "solidarity" with the people of New Zealand and Muslims around the world.