A prime minister can decline to direct a conscience vote without escaping responsibility for the law that follows. On assisted dying, I think that distinction deserves preserving.
The argument reaches beyond an ordinary disagreement about a government programme. It concerns suffering, autonomy, protection from pressure and the responsibilities of the state. MPs should have room to consider those questions without being told that one answer demonstrates loyalty to their leader.
Restraint can have a purpose
A leader's preference can influence a vote even where no formal instruction is given. Ministers look to the centre, backbenchers look to ministers, and a supposedly free decision can acquire the atmosphere of a loyalty test.
There is therefore a serious case for restraint. It can make room for uncertainty and disagreement that a subject of this gravity requires.
But restraint over the vote isn't permission to neglect implementation. A law would create duties for institutions and expectations for families. Government still needs to assess what those duties require and whether the proposed system can fulfil them.
Consider the difficult cases
The case for change shouldn't be dismissed as mere sentiment. People experiencing profound suffering deserve to be heard, and it would be wrong to assume that every person seeking greater control has been pressured into it.
The concern about pressure is serious too. Dependence, loneliness, exhausted relatives or inadequate support can affect how a person understands their choices. A formal safeguard has to work in those circumstances, rather than only in the clearest example offered in a speech.
Parliament needs to examine how decisions would be assessed, how disputes would be handled and what support people would receive. Neither compassion nor caution removes the need for that practical scrutiny.
A prime minister needn't instruct MPs how to vote to insist that these questions receive answers. MPs should own their judgement, and the government should own its responsibilities for the system Parliament creates. Avoiding one form of influence shouldn't become an excuse to avoid the consequences.