This government has introduced several Bills which are against the interests of 99% of the UK population. We and other organisations are campaigning against them. To campaign effectively, it is crucial to understand how Bills become law and how bad Bills can be scrapped or amended.

This article explains both the normal process by which a Bill becomes law and the most likely ways it can fail to become law. It also covers the ways a Bill can be amended. It relates to Bills proposed by the government of the day, which generally do become law, not to Private Members’ Bills or other Bills which are unlikely to become law.

In summary, the normal process for government Bills allows for amendments and these are frequent and can be material. In principle, there are also many ways for a Bill to be defeated in its entirety, but in practice, unless the government of the day falls or at least loses its majority, they are very unusual.

The best way to campaign against a Bill, while the government retains a large majority, is to amend its damaging provisions.

The Normal Process

The most common process for a Bill to become law is set out in the diagram below and described in more detail in Appendix I. It is also possible for a Bill to originate in the House of Lords, in which case the top two lines of the diagram below are switched, but this is less common.

Most Bills begin in the Commons, where they have their first and second readings. The First Reading is largely a formality; the second includes a debate on the principles of the Bill and the house decides whether the Bill should proceed.

If it passes its Second Reading, the Bill enters the Committee Stage where it is considered in great detail. The Committee can take input from external experts, and every clause in the Bill is agreed to, changed or removed from the Bill.

The Bill then enters the Report Stage where MPs have an opportunity, on the floor of the House, to consider further amendments to a Bill which has been examined in committee.

Finally, before it leaves the Commons, the Bill has its Third Reading, which is usually a short debate followed by a confirmatory vote.

The Bill then passes to the Lords where it undergoes a similar (though not identical – see Appendix) process and returns to the Commons for consideration of Lords’ Amendments. Since both Houses must agree on the exact wording of the Bill, if the Commons declines to accept or modifies any of the Lords’ amendments, the Bill must then return to the Lords for consideration of the Commons’ amendments, etc. This to-and-fro process is referred to as ‘ping-pong.’

Once the Commons and Lords agree on the final version of the Bill, it can receive Royal Assent and become an Act of Parliament (the proposals of the Bill now become law).

The most likely ways a Bill can fail to become law

There are several extraordinary ways in which a Bill could, in principle, fail to become law, such as the Queen refusing to give Royal Assent, but these would provoke a constitutional crisis and have not happened in recent history.

The most likely ways for a Bill to fail absolutely are:

  • For a controversial Bill proposed by a government with a small majority to fail to get its second or third reading in the Commons;
  • For a controversial Bill proposed by a government to fail to get its second reading in the Lords;
  • For a Bill to run out of time in a parliamentary session – for example due to protracted ping-pong.

A Bill can fail to get its second or third reading in the Commons

It is in principle possible at second or third reading in the Commons to introduce a ‘reasoned amendment’ to vote down the entire Bill, but these are rarely voted on[1]. The Second Reading is the first stage at which a Government bill can be defeated, but this has not happened since 1986[2] when the Shops Bill was defeated in the Commons.

A Bill can fail to get its second reading in the Lords

Bills are also rarely rejected by the Lords at second reading as a vote to reject the Bill represents a direct challenge to the principle of the Bill. Government Bills included in the election manifesto are, by convention, not opposed at second reading in the Lords, but ‘reasoned’ amendments may be tabled as a means of indicating dissent and can be voted on. There have only been three Bills rejected at second reading in the Lords[3] since the year 2000:

  • Fraud (Trials without a Jury) Bill: rejected 20 March 2007;
  • Assisted Dying for the Terminally Ill Bill: rejected 12 May 2006;
  • Criminal Justice (Mode of Trial) (No. 2) Bill: rejected 28 September 2000.

A Bill can run out of time

For a Bill to run out of time – i.e. it has not had Royal Assent by the time that Parliament is prorogued – is not unheard of. When this happens, there are ways the Bill can be carried over[4] into the next session of parliament. This usually means that the Bill is delayed rather than defeated. Of course, a Bill which has not become law by the time a government falls is unlikely to be carried over.

Amending Bills

If a Bill does not fail absolutely, it may still be substantially amended. There are complex rules about which kinds of amendments may be tabled at each stage[5], but substantial amendments are still possible. A recent example is the Police, Crime, Sentencing and Courts Bill which suffered a number of significant government defeats[6] in the House of Lords. If substantial amendment happens, the Bill gets through, but it is not the ‘same’ Bill.

In practice, substantial amendment is the most likely route to harm reduction for a damaging Bill.


In theory, there are many ways a Bill can be defeated in its entirety. In practice, unless the government falls or loses it majority, these are very unlikely. It is not, however, uncommon for Bills to be amended, especially in the House of Lords.

If a government with a large majority introduces a harmful Bill, it is more likely that the harm can be reduced by amending it than by an all-or-nothing strategy of trying to stop it in its entirety.

If you would like to help us prevent this government passing more damaging legislation, please sign up and join the 99% Organisation.

If there are specific Bills you would like to see amended, these notes may help you to secure your MP’s commitment.



[1] (Institute for Government, 2022)

[2] (House of Commons Information Office, 2010)

[3] (UK Parliament, 2022)

[4] (Kelly, 2021)

[5] (House of Commons, 2022)

[6] (The Constitution Unit — UCL, 2022)


House of Commons. (2022, 2 16). Tabling amendments to Bills. Retrieved from

House of Commons Information Office. (2010, 8). Parliamentary Stages . Retrieved from

Institute for Government. (2022, 2 16). How are bills amended by Parliament? Retrieved from

Kelly, R. (2021, 4 30). Carry-over of public bills. Retrieved from

The Constitution Unit — UCL. (2022, 2 16). Retrieved from Government Defeats in the House of Lords:

UK Parliament. (2022, 2 16). FAQs: What was the last Bill rejected by the Lords at second reading? Retrieved from

UK Parliament. (2022, 2 16). How does a bill become a law? Retrieved from