Former prime minister Jacinda Ardern will depart Parliament this week for a role working on the Christchurch Call.

She will also work alongside Prince William, on a climate change charity he founded. William, the next in line to the British throne, confirmed Ardern's role on the Earthshot Prize board – which he sits on as its president.

'Four years ago, before The Earthshot Prize even had a name, Jacinda was one of the first people I spoke to, and her encouragement and advice was crucial to the prize's early success. I am hugely grateful to her for joining us,” he says.

Prime Minister Chris Hipkins earlier hinted that Ardern would be working on the Christchurch Call. Her role, as a 'special envoy”, would see her report directly to the prime minister.

Although this would be her job post-politics, a statement from Hipkins' office said Ardern would not be paid for it.

'Jacinda Ardern has declined to receive any remuneration as Special Envoy, and will commence her role on 17 April,” it said.

The Christchurch Call was launched by Ardern in the wake of the March 15 terror attack.

It sought to achieve global cooperation from other nations and from social media and tech giants, to combat the spread of terrorist activity and propaganda online.

The attacks on two Christchurch mosques were livestreamed on Facebook, which inspired other killers to stream murders on social media.

Alongside French president Emmanuel Macron, Ardern launched the Christchurch Call summit in May 2019.

Since then, more than 120 countries have signed up to the unenforceable call to action and promised to take action to limit the spread of violence and terrorism through social media.

Work on the call has included research into algorithms and the establishment of a multinational emergency taskforce to monitor and remove terrorist content when attacks occur.

In a statement, Hipkins says Ardern's global connections and commitment to the Christchurch Call meant she was well-placed to take on the special envoy position.

'The Christchurch Call is a foreign policy priority for the Government and Jacinda Ardern is uniquely placed to keep pushing forward with the goal of eliminating violent extremist content online,” he says.

”Ardern's leadership on the Christchurch Call has already made New Zealand, and the world, a safer place.”

Her leadership after the March 15 attack was remembered by many around Parliament as a defining moment of her prime ministership.

Even Opposition MPs paid tribute to her work as a diplomat and globally recognised leader on Tuesday.

Judith Collins, who ran against Ardern as National's leader at the 2020 election, says her international presence had been 'extraordinary”. However, she says Ardern's Government had struggled to make progress on matters other than Covid-19 and responding to the terror attack.

Ardern announced her resignation with little warning during a Labour caucus retreat to Napier in January. Less than a week later, Hipkins had been sworn in as prime minister.

Ardern remained an MP, representing Mt Albert, so as not to trigger a by-election. She is scheduled to deliver her valedictory speech on Wednesday, marking the end to her 15 years in Parliament.

The final speech to Parliament is expected at 5.30pm. Stuff will livestream the speech.

Since announcing her resignation, Ardern has spent little time in Parliament.

She returned on Tuesday to attend the weekly Labour Party caucus meeting. Labour MPs arrived with various gifts and lei, to farewell Ardern.

She avoided speaking to reporters on her way in, other than to say she was feeling 'great” on her last week in Parliament.

On January 25, Ardern formally finished the job as prime minister by meeting with Governor-General Dame Cindy Kiro.

That morning, she left the Beehive to a guard of honour stretching across the Parliament forecourt, made up of Labour MPs, staffers, Green Party supporters and members of the public.

- Glenn McConnell/Stuff.