Analysis: It’s fast approaching that point in the election cycle where MPs decide whether they have another campaign in them. Some in the Labour Party have already made their minds up, writes political editor Jo Moir.

There will be MPs who have tough decisions to make in the coming months about whether their hearts are still in politics.

But for others the decision will be made for them, with the knowledge they aren’t destined for a senior role or a decent place on their party list.

Labour’s president, Claire Szabó, is already hitting the phones checking in with electorate MPs about their plans to run in their seats, or at all in the general election next year.

The halfway point of the term came and went two weeks ago and it’s not unusual for attentions to now turn to who will and won’t be sticking around.

From a Government perspective, those decisions feed into any reshuffle ahead of the election and help inform people’s place on the party list next year.

Deputy Prime Minister Grant Robertson told Newsroom last month that during every term “you get to a point where you start having people say if they’re going to run again or not’’.

He expects those decisions won’t be made until later in the year but when they are they’ll “trigger other movements’’, such as a Cabinet reshuffle.

Tamaki Makaurau MP Peeni Henare has already indicated to Szabó he isn’t very keen to fight through another campaign and would prefer to go list-only.

Three senior MPs in the party are approaching or will have hit three decades of service by next year’s election.

Speaker of the House Trevor Mallard entered Parliament in 1984 and is nearing 36 years in the House (he was out for one term after the 1990 election).

Mallard isn’t planning to run at the next election but at this stage has no plans to retire before then.

He is frank that no Speaker has ever completed two terms, and there has been speculation that he might be in the running for a diplomatic post in Dublin.

If not a diplomatic post, Mallard will be 68 next month and would be just as happy spending more time with his grandchildren and racing his road bike.

West Coast-Tasman MP and Trade Minister Damien O’Connor will have been in Parliament just shy of 30 years by the next election.

O’Connor has been relishing his trade and agriculture ministerial portfolios, and with borders opening up is out on the world stage negotiating trade talks.

He will be 65 next year and might like the idea of retirement but Labour will be careful to make sure they retain some ministerial experience and O’Connor is one of the few who offer a rural farming background, which Labour needs to hold onto.

Nanaia Mahuta joined Parliament in 1996 and will have served for 27 years at the election.

While there’s been years of speculation about her leaving to take up royal responsibilities within Kiingitanga, that has not eventuated and Tuheitia is still the Māori King.

Mahuta is a well-known homebody and has struggled with the pressure to be overseas in her foreign affairs role.

For that reason, her local government portfolio has been where her energies have mostly sat.

Mahuta lost the support of Kiingitanga at the last election – Tuheitia backed the Māori Party candidate instead – yet, she still won the seat of Hauraki-Waikato.

She proved she can win the support of her constituents on her own, and Waikato is where she prefers to spend her time.

Attorney-General David Parker is the other most senior and experienced member of Cabinet – he will have served 18 years next year.

Parker has been open with colleagues that he’ll leave when his work is all on course to be complete.

The reform of the Resource Management Act has been his biggest project in the past four years and with legislation underway and a timeline locked in, Parker could almost see that as job done.

He’ll also be hoping to get the Kermadec Sanctuary across the line this term, though that might prove slightly more difficult.

Parker is another whose experience and smarts are valuable within the Labour caucus, and he would leave a big hole if he was to go.

Succession planning has been almost non-existent in political parties in recent years, which is why both Labour and National have both gone through such significant implosions while in opposition.

No obvious leadership potential makes it difficult to maintain caucus discipline.

Szabó will be mindful of this not only from a leadership point of view, but in electorate seats as well, where there’s a need for obvious successors to take over when long-serving MPs call time.

Justice Minister Kris Faafoi told the party he was done last term but was encouraged to stay – the compromise was him being moved to the list and Barbara Edmonds running in his safe Mana seat to free him up to move his family to Wairarapa.

Labour will struggle to convince him to do another term.

With the RNZ/TVNZ merger progressing and some of his immigration and justice reforms underway, Faafoi will leave having ticked off a few big items.

There are question marks over whether Panmure-Ōtāhuhu MP Jenny Salesa will stay on or call it quits after failing to make it into Jacinda Ardern’s post-2020 Cabinet.

Salesa struggled as a minister last term. She was demoted out of Cabinet and made assistant speaker.

Her colleague and deputy speaker, Te Tai Hauāuru MP Adrian Rurawhe, has been well received across the House when he has stepped into the speaker role during Question Time this term.

His style is very different to Mallard’s, who can agitate both sides of the House with his regular interruptions during answers and debate.

Rurawhe is much more hands-off but is increasingly assertive when he needs to be.

If he lands in the Speaker's chair next term, the party would need to have a successor for his Māori electorate.

Currently there is no obvious replacement, and Rurawhe has fought off many battles in that seat because of the strong support and connection he has with the Ratana church.

Labour would be nervous about leaving the seat open for Te Pati Māori co-leader Debbie Ngarewa-Packer to slide into, especially given it is her home and she has done a lot of leg work – particularly around vaccination - in the electorate.

But that isn’t the only Māori seat in play.

Tamaki Makaurau MP Peeni Henare has already indicated to Szabó he isn’t very keen to fight through another campaign and would prefer to go list-only.

Henare has had three gruelling battles in that seat, defying critics by successfully beating Greens’ co-leader Marama Davidson and Te Pati Māori candidates, including John Tamihere.

It’s also unclear whether Meka Whaitiri will commit to another campaign in the Tairāwhiti seat, although she has fought her way back into Cabinet after many had written her off.

And while some MPs need to decide if they want to stick it out for another three years, potentially on opposition backbenches, there are other parties who need to concentrate on finding good candidates to challenge Labour in 2023.

Polls to date suggest another single-party majority is highly unlikely, which means National, ACT, the Greens and Te Pati Māori will all be on the hunt for candidates to go up against those Labour MPs who picked up seats in the big red tidal wave of 2020.

Some in Labour who rode that wave into Parliament will be well aware they may not be returning, and that in itself means decisions need to be made about their future, outside politics.