As it happened: Bill English addresses the nation

Former Prime Minister Bill English is stepping down as National party leader and will be leaving Parliament later this month, he announced on Tuesday morning. 

Mr English will serve his last day as leader and an MP on February 27, and will give a valedictory speech in March. 

He has not nominated a replacement, instead saying it was up to the caucus MPs to decide on a new leader.

National MP Steven Joyce would not comment about who the next leader might be, saying "today is Bill's day" and the discussions would begin tomorrow. 

Here's how the day unfolded: 

3:20pm: Australian Prime Minister Malcolm Turnbull has congratulated Mr English on his service to New Zealand.

"Congratulations Bill English on a great career in public life. NZ’s strong economy is due in large measure to your hard work as Finance Minister & PM over many years. All good wishes to you, Mary and your family," he said on Twitter.

2:25pm: Former prime minister John Key has shared a message for Mr English:

"Like so many Kiwis I am saddened to hear my close friend Bill English is leaving Parliament. Bull has given remarkable service to a party and a country he loves.

"His dry wit outstanding economic leadership and rolled Rs will be missed.

Enjoy your new life mate," he said.

 2:05pm: Deputy Prime Minister Winston Peters says politics is a rough game and "we knew a for a long time that the knives were out" for Mr English.

"All sorts of contenders will be claiming a potential victory for themselves. Whoever the next leader is is not going to be successful, that I can guarantee you," he said.

Asked whether Mr Peters' decision to work with Labour was what pushed Mr English out, the NZ First leader said: "That's a view that some people might hold but the reality is we made a choice in the interests of the country, having regard to the economic and social malaise that much of our country's in."

Mr Peters said particular problems were in the regions and in areas affected by the housing crisis.

"So that's the price you pay for running an economic agenda for the few against the interests of the many."

He said Mr English had provided stability "under a very flight leader called John Key". 

"But in the end if you look at the concretisation of wealth in so few hands in that period of time this cannot be regarded as a period of success economically." 

At the closing of Parliament last year, Mr Peters gave odds for who the next National leader would be. 

"The most dangerous place to be right now is the National Party front bench," he said.

2pm: National MP Steven Joyce said: "It's been a tremendous 27 years of public service and he's earned the right to out when he chooses, and that's what he's done."

Mr Joyce said National has every intention to compete and win the 2020 election.

"As Bill says it's a vulnerable government that is going to get found out over the next couple of years and it's our job to make sure that happens." 

1:05pm: Green MP Julie Anne Genter has endorsed Judith "crusher" Collins to be the next leader of the National party.

"It's time for a woman who cares about politics," she said.

It seems Ms Genter is returning the favour after Ms Collins endorsed her to be the new Green co-leader, tweeting "At least Julie Anne is sane. She should win."

12:50pm: National MP Nikki Kaye said Mr English is a "rare breed of politician" and she's "really gutted" about the news.

In a tribute on her Facebook page Ms Kaye said: "He has achieved such a huge amount in 28 years. The sheer number of achievements, his depth emotionally, politically and intellectually, his understanding of policy and the machinery of government, his integrity and his strong social conscience to help some of our most vulnerable make him someone that history will look kindly on and will single out."

She says he will leave a "massive hole" in New Zealand politics and in the National party. She mentioned that Mr English is one of the people who sparked her interest in politics, and said he and former prime minister John Key helped her come back (after she took leave during her struggle with breast cancer).

 12:35pm: Federated Farmers president Katie Milne said Mr English can leave Parliament "with his head held high".

"He’s scheduled to take part in a sheep shearing event at the South Island Field Days on Friday and if he makes it, there will be plenty of farmers lined up to salute him," she said.

"He demonstrated he wasn’t just an astute manager of the nation’s finances, but through his approach to social investment revealed he was a caring leader who really wanted to make a difference for the less-well off."

12:30pm: Green co-leader James Shaw acknowledged Mr English, his wife Mary, and his entire family for their sacrifice.

"Anybody who's involved in politics is aware of the great personal sacrifice that is required to do this job, for both the politician and their loved ones," Mr Shaw said.

"For that reason, I'd also like to acknowledge Mary English and the entire English family. On behalf of the Green Party, I’d like to wish Mr English and his family all the best for the future."

He said Mr English should be congratulated for his perseverance and commitment to politics over the past 27 years.

12:25pm:

Green MP Julie-Anne Genter said on Twitter that she didn't usually agree with Mr English about policy, but respected that he was "open to thoughtful debate" and "his motivation comes from his values". 

12:20pm: ACT MP David Seymour says Mr English's resignation is "a loss to Parliament".

12:15pm: Finance Minister Grant Robertson says that despite disagreeing with Mr English "a fair bit", he admires his contribution to politics. 

12:05pm: National deputy leader Paula Bennett has spoken on behalf of the party caucus about their leader's resignation.

"Today is tinged with sadness, Bill is man that has incredibly mana, incredible respect amongst all of caucus members. He has led us so incredibly well and done such a great job with us. So we're going to miss him and miss him a lot," she said. 

"I just don't think New Zealand will ever fully appreciate the depth of his thinking, everything that he's given to them, we're just so proud to have had him as our leader and as our Prime Minister. "

Ms Bennett did not respond when asked whether she wants to be the next leader.

12:00pm: Former United Future leader Peter Dunne says Mr English is a "good, decent, caring man" and he's also sought to assure him "there is life after politics". 

11:56am: Māori Party co-leader Marama Fox has paid tribute to Mr English.

She believes his legacy has been to support Whanau Ora and bring an independent Māori voice to Parliament. 

11:52am: Jacinda Ardern has given Mr English her best wishes on Twitter.

"Just heard the news that Bill English has decided to stand down," she wrote.

"Bill has made a huge contribution through his time in office and to politics generally.

"I admire those who serve NZ in this place, and Bill did for a long time, and he did it well."

11:48am: Mr English says he doesn't have a view on whether National should opt to stick with experience or look ahead to the new generation.

"I'll just have a vote like everyone else, in the process. I expect I might enjoy having them come and ask me for it," he said with a laugh.

11:44am: Mr English will deliver his valedictory speech on Thursday, March 1, two days after his last day as National leader.

11:42am: The tears came as he thanked his wife Mary and his six children.

"For all our time together we have lived with demands of public service," he said.

"Your strength and tolerance has enabled my career. You have been my inspiration and pride and I now look forward to a new life together."

11:38am: Mr English has announced not only is he stepping down from National Party leadership, but will also leave Parliament.

He shed tears at the back end of his resignation speech.

"I've come to work every day with a sense of mission," he said.

"It's been an absolute pleasure to lead a party that represented you and your values."

11:34am: "Now is the time to step aside," he said.

"It's been a pleasure to serve in Parliament."

Mr English's resignation will take effect on Tuesday, February 27.

11:30am: Mr English is expected to begin speaking from Wellington any minute now.