One of the most important votes of this parliament will take place in less than three weeks – and MPs are hesitating.

The long-awaited assisted dying bill is due to be published amid growing concerns that there will not be enough time to scrutinize the legislation.

Kim Leadbeater, the MP for Spen Valley whose private members’ bill is the vehicle for changing the law, is pushing ahead and will make the case in the next few weeks.

It will be a critical time with so many undecided MPs and little indication of where the parliamentary numbers currently stand.

Watch: What is assisted dying?

Widespread attention

The last time lawmakers voted to legalize assisted dying in 2015, it was decisively defeated by 330 to 118.

But the Commons has changed beyond all recognition since then, and so, it is said, has a feeling on the subject.

But there is widespread caution as lawmakers from all parties reach out to their constituents through public meetings and polls before making up their minds, with many genuinely undecided.

Others worry that the bill needs much more time given the gravity of the subject.

And in Labor circles, a growing sense that such a seismic shift will define their time in office, for better or worse, despite it being a free vote.

Against this uncertain backdrop, details of the bill will be revealed as decision time looms with the second reading and accompanying Commons vote set for November 29.