Tomorrow MPs will vote on the highly controversial assisted dying bill, which seeks to grant adults suffering from terminal illness the right to choose to end their life on their own terms.

Championed by Labour backbench MP Kim Leadbeater, the bill would apply to those who are over 18 years old, have mental capacity, and have six months left to live, with the consent of two medical professionals.

The bill has been fast-tracked to a vote after being first introduced as a Private Members’ Bill (PMB) in mid-October, which are bills introduced by MPs and peers who are not Government ministers.

But it has generated controversy from members of the house on both sides of the debate, who are concerned about the speed in which the bill is being brought to a vote, and a perceived lack of safeguarding measures.

The bill is being put to a ‘free vote’ on Friday, which means MPs are able to vote according to their own personal values and those of their constituents, rather than being advised to vote a certain way by party whips.

If passed, the assisted dying bill will become one of the most significant Private Members’ Bills to be written into law in recent memory.

So what exactly are Private Members’ Bills and why are they so hard to pass?

What is a Private Members’ Bill?

Private Members’ Bills are proposals for new laws or changes to existing ones brought forward by MPs who are not part of the government. They serve a crucial role in allowing backbench or opposition MPs a chance to shape the legislative agenda and champion causes that were not part of the ruling party’s manifesto.

Unlike government bills, which are tied to the administration’s official priorities, Private Members’ Bills often highlight niche issues, personal causes, or emerging social concerns. While they rarely become law, their importance lies in sparking debates, influencing public opinion, and occasionally pushing the government to take action on overlooked topics.

Private Members’ Bills also allow the government to test the parliamentary appetite for a change in the law on significant issues without publicly committing to them if they end up being too controversial.

This method has been used to test the waters on some of the biggest social reforms in modern times, such as abortion, civil partnerships and the decriminalisation of homosexuality.

How are they different from Government Bills?

The key difference between a Private Members’ Bill and a government bill lies in who introduces it.

Private Members’ Bills are put forward by MPs outside the Government, whereas Government bills are the product of ministers and reflect the administration’s main legislative agenda.

Government bills have a much higher success rate. They get prioritised in the legislative schedule, benefit from dedicated time for debate, and are usually backed by the ruling party.

But Private Members’ Bills are often have specific time slots and may not gather enough support to progress further. While government bills are backed by civil servants and expert advice, Private Members’ Bills rely on the resources and initiative of the individual MP who proposes them.

There are two ways to get a Private Members’ Bill tabled for debate – a Ballot Bill and the Ten Minute Rule. Due to the high number of MPs who want to table Private Members’ Bills, the start of each Parliament session sees backbench MPs who wish to table one put their names into a ballot.

Twenty-five of these are then selected to be ‘Ballot Bills’, which take priority over other Private Members’ Bills and are allocated time for debates, giving them a better chance of becoming law. 

The other way of tabling a Private Members’ Bill is through a process called the ‘Ten Minute Rule’, where MPs are given a ten-minute window in parliament to outline their position, which another member may oppose with a similar short statement. These are seen as good opportunities to raise the profile of an issue and to see whether it has support among other MPs.

Ms Leadbeater was the first MP of the current parliament to be granted a Ballot Bill, which she responded to by tabling the assisted dying bill.

Why are Private Members’ Bills difficult to Get Passed Into Law?

Private Members’ Bills face significant challenges on their path to becoming law, making their success rare. First, they often struggle to secure time for discussion. Parliaments usually allocate specific and limited slots for debating Private Members’ Bills, leaving many proposals unheard or unfinished.

Even when a Private Members’ Bill does make it to debate, it must overcome significant political hurdles. Without government backing, it can be difficult to rally the majority support needed for passage. Many legislators may hesitate to prioritise a Private Members’ Bill over government-sponsored bills or may see it as less urgent.

Another barrier is the lack of resources. While government bills benefit from thorough preparation and input from legal and policy experts, Private Members’ Bills depend on the efforts of the individual member who introduces them. This can make them less polished or harder to implement effectively, reducing their appeal to other legislators.

Despite these difficulties, Private Members’ Bills are still valuable. They raise awareness about niche or emerging issues, influence public discourse, and occasionally compel the government to adopt ideas they initially overlooked.

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