Many MPs are torn over the issue but believe more debate is better so their vote is in support of more debate, rather than support of the bill.
And the role of New Zealand First in the process is crucial. The party's power extends beyond Coalition politics to this conscience vote because of its bid to get the issue put to a referendum.
Normally Seymour would play the devil to New Zealand First, but it has done a deal with him to support the bill on condition he supports their referendum amendment.
If its bid to get a people's referendum is rejected in the committee stage, it is not yet clear how the nine MPs would vote, although it would be wrong to assume anything.
Act Party leader David Seymour, and the bill's sponsor, has already agreed to drop the most contentious part – allowing assisted dying to people without a terminal illness but who are suffering with a grievous and irremediable condition. Photo / Mark Mitchell
Despite being considered a socially conservative party, an overwhelming majority of its MPs voted in support of the last euthanasia bill in 2003, including leader Winston Peters, which was sponsored by the party's deputy leader at the time, Peter Brown (nine in favour, three against and one abstention).
The proponents of the current bill have a few weeks to finesse their strategy before the protracted committee stages when amendments will be put up including the referendum and one adding an extra hurdle to the approval process for euthanasia, the Family Court.
It won't be enough to simply say nobody else does it that way.
The proponents will have to ask themselves whether it is worth compromising their beliefs on individual choice by allowing amendments that may make it harder to exercise that choice. But that could ultimately get the bill across the line after years of trying.
It has been a long process. MP Nikki Kaye called it a 16-year process. That is when the last euthanasia vote occurred. This may be the last chance for a long time.
One way or another, the issue has been continuously before the House for four years through the health committee inquiry that began in 2015 and which received more than 21,000 submissions. The current bill received more than 39,000 submissions.
Twelve MPs changed their vote between the first and second reading of Seymour's bill.
National's Judith Collins is among three MPs who previously opposed the bill and now support it. Photo / Mark Mitchell
Three who previously opposed it now supported it: Judith Collins, Poto Williams and Lawrence Yule.
But most of the reverse traffic was in the other direction.
Nine who supported it at the first reading voted against it at the second reading: Kiritapu Allan, Nathan Guy, Harete Hipango, Deborah Russell, Adrian Rurawhe, Anne Tolley, Hamish Walker, Meka Whaitiri and Michael Wood.
And, as Mark Mitchell and Willie Jackson pointed out in their speeches, while they were voting for it at the second reading, there was no guarantee they would continue to do so.
There is a soft vote which is deeply concerned about the insidious pressure that could be applied to vulnerable people, particularly the elderly, and those already suffering from a grievous condition.
The anguish was articulated in some excellent speeches such as those by Jackson, Wood, Russell and Louise Upston.
Wood talked about not overt pressure, but the implicit pressure of some who feel like a burden on their families.
Willie Jackson says, while he voted for the euthanasia bill at the second reading, there is no guarantee he will continue to do so. Photo / Mark Mitchell
Jackson gave one his best speeches as he talked about the Māori caucus and how it was split down the middle and the pressures on their decision.
He talked about his upbringing in a whānau where there was no such thing as individual rights, an upbringing in which the collective whānau decided everything.
Essentially he was saying he would support the bill at second reading but it went against the values he was brought up with and he doesn't know how he will vote in the third reading.
Seymour has already agreed to drop the most contentious part of the bill – allowing assisted dying to people without a terminal illness but who are suffering with a grievous and irremediable condition.
He lifted it from a Canadian Supreme Court judgment and subsequent statute law and clearly it was a mistake to have put it in there at all.
It has been a legitimate rallying point for the disability sector in New Zealand whose concerns have shifted views, and it has led to suspicion about an extreme agenda from the bill's supporters.
The select committee abrogated its responsibility in not removing the clause from its reported-back version when clearly there was overwhelming support to do so, including from the bill's sponsor.
Opinions over the referendum are divided. It will be the last amendment put, being about when the bill will take effect from.
Pacific Island people rally to oppose the End of Life Bill at Parliament in April. Photo / Mark Mitchell
After that issue has been determined, there may be only two or three votes in the final vote. That should be an incentive for Seymour and his team to make more effort to find an extra safeguard.
The bid to involve the Family Court as a final authority is worth considering.
One more hoop just might force the two medical practitioners to be that much more vigilant in assessing whether there has been pressure on a vulnerable patient.
So far, team Seymour has been dismissive of the Family Court amendment.
The final vote could be close. Seymour might feel vindicated in having stuck religiously to two medical practitioners having the final say if he wins by one or two.
But it's a position he might live to regret if he loses by just one or two.
