As leader, Mr English will get to choose the date of next year's election. Before the leadership change most people had expected it to be held in September, but some lawmakers are now calling for an earlier vote.

The other contenders for the role were health minister Jonathan Coleman and corrections minister Judith Collins. Both said they would now back Mr English.

"I'm going to be supporting him 100 percent," Mr Coleman said. "It is absolutely vital that the party comes together and gets on with the job of winning the next election."