Assisted dying bill: What happens next?

The draft law that would legalise assisted dying in some circumstances in England and Wales has cleared all of its initial stages in the House of Commons.

MPs voted in favour of the Terminally Ill Adults (End of Life) Bill in principle back in November by a majority of 55.

Now, after many hours of sometimes fractious debate about the details of the bill, it has been passed by 314 votes to 291, a majority of 23.

But that does not mean it will immediately become law.

It now has to go through all the stages it went through in the Commons in the House of Lords - and then MPs will get a final say when they have looked at any changes suggested by peers.

This is the point the bill will officially become law - unless it runs out of Parliamentary time or peers opposed to it find a way of blocking it.

Like MPs, peers will get a free vote, meaning they are allowed to follow their conscience rather than orders from party managers.

The BBC understands supporters of the bill feel there's a majority in favour in the Lords. But until peers actually vote, that's just an informed guess.

What is certain that the many experts on the Lords benches, which includes doctors, lawyers, disability rights activists and Bishops, will want to have their say on it - both for and against.

The House of Lords does not normally block government bills from becoming law - but assisted dying is not a government bill.

It is a private members' bill, sponsored by a backbench Labour MP, Kim Leadbeater. The government is officially neutral on the bill, although it will try to ensure Parliamentary time is made available to debate it.

Lord Falconer, a long time campaigner for assisted dying who was justice secretary under Tony Blair, is hoping to shepherd the bill through the Lords.

He says he is sure peers will "respect the views taken by the Commons on this".

"Ultimately it is for the Commons to decide on whether we should have an assisted dying law, and what its shape will be," he told a press conference on Thursday.

"And we in the Lords will do what we do best, which is scrutinise the details, but leave the main decisions to the Commons."

Baroness Finlay, who is a palliative care doctor and who is against the Bill, told the BBC that "our role is not to rubber stamp whatever has happened in the Commons, particularly when we know that so many amendments put down in the Commons that would have improved the Bill have gone undebated."

Members of the House of Lords who oppose the law may now feel that the momentum is with them.

They are likely to feel fortified by the majority in the House of Commons at third reading being relatively slim, and having shrunk since the second reading vote in November. They will argue that the narrow majority gives them a particular mandate and duty to scrutinise the bill as closely as possible.

Even in that context, though, there will be extreme wariness about being seen to stop the passage of something so significant which the House of Commons has endorsed.

One of the biggest worries, for supporters of assisted dying, is that the Bill could run out of time.

Parliamentary time is divided into what are known as sessions. These tend to be around a year long - although this can vary greatly.

Bills generally have to complete all their stages within one session. Government bills can be "carried over" to a second session, but because the assisted dying bill is a private members' bill it can't be.

The bill took almost seven months from its first debate to completing its steps in the Commons. Supporters of the Bill expect it to take several months to pass the Lords.

The current session began 11 months ago, which would suggest there won't be enough time to get the bill through the Lords and it would "fall" before becoming law.

It's doesn't look like the current session is ending any time soon however. It's the government's choice when to start a new session and it still has lots of its own legislation to get through.

Some supporters of the bill believe the new session will start in December at the earliest, which would provide more than enough time for it to pass both Houses of Parliament.

Alternatively, if the next session were to begin in the autumn, that would give the bill a few weeks after the summer recess to get through the Lords - although it would be tight.

Peers who are strongly against assisted dying could try and stop it through tabling lots of amendments.

In the Commons, a hundred MPs can over-ride such tactics, if they support a "closure motion" which allows a bill to be forced to a vote - but it doesn't work like that in the Lords.

MPs could also decide to reject any amendments peers make to the Bill. That would see it go back and forth between the two Houses of Parliament, known as ping pong.

If MPs and peers keep disagreeing this would mean it takes the Bill even longer to become law, and a much greater chance of it running out of time.

Commons rules dictate that private members' bills are only debated on a Friday.

There are currently only two Fridays left to debate them, meaning the government would have to schedule more.

The bill says that the implementation of assisted dying will take up to four years.

Depending on how long the Lords takes to pass the bill (if they do at all), that means it could be late 2029 by the time a terminally ill person would be able to legally access an assisted death.

The initial plan was that the bill would take two years to implement, which would have put the first potential legal assisted deaths in late 2027.

But changes made to the bill during committee stage will take longer to put into place in practice, according it sponsor Leadbeater.

That is most notably the replacement of the role of a high court judge with a panel of experts in signing off an assisted death.

It's possible the bill could be implemented more quickly than four years. A spokesperson for Leadbeater has previously said that "the four year limit is not a target, it's a backstop".