How are bills amended by parliament?

Amendments are proposals to change, remove or add to the existing wording of bills to modify their effect.

19 JUL 2019 This explainer was updated on 16 January 2024.

Houses of Parliament

What are amendments to bills?

Amendments are proposals to change, remove or add to the existing wording of bills (draft legislation) to modify their effect. Parliament’s ability to propose such changes is an important part of the legislative scrutiny process.

Different processes apply to amendments to motions. Motions are statements that outline a topic for Parliament to discuss or a question for it to decide. They help to structure parliamentary debate.

Who can make amendments?

In most cases, bills can be amended by both the Commons and the Lords. However, there is no Lords committee stage for ‘bills of aids and supplies’” which authorise taxation (such as finance bills) or ‘appropriation bills’ which authorise government spending – the Lords cannot therefore amend such bills.

Amendments may be tabled by any MP or Peer.

Why are amendments proposed?

Most amendments agreed to are proposed by the Government. They may be proposed for several reasons:

Although amendments must be passed in order to ‘stand part’ of a bill— in other words, to be incorporated into the legislation and have legal effect—even amendments that do not pass can still have political effects. This is often the case with non-government amendments, which can sometimes be proposed for other reasons:

When can amendments be made?

Parliamentary stage

When does it happen?

What happens in the Commons?

What happens in the Lords?

Commons

If the bill is to be debated in a Public Bill Committee:

The timeframe may be compressed for bills debated in Committee of the whole House.

Lords

At least 14 calendar days after

Committee stage usually takes place in a Public Bill Committee (formed of a group of MPs and chaired by a member of the Panel of Chairs).

Important, urgent, or very minor bills may be debated in Committee of the whole House (when the bill is debated on the floor of the House of Commons).

Amendments are routinely tabled and voted upon at committee stage.

Amendments can be tabled as soon as second reading has finished. Amendments tabled less than three sitting days before they are due for debate might not be selected for debate.

Committee stage takes place on the floor of the House or in ‘Grand Committee’ (where any member may speak but there are no votes).

Amendments are routinely tabled, but rarely pushed to a vote at committee stage.

Amendments can be tabled as soon as second reading has finished. They must be tabled at least two sitting days before they are due to be considered.

Commons

Usually at least a week after committee stage.

There is no Commons report stage if a bill has its committee stage in Committee of the whole House and survives unamended.

Lords

At least 14 sitting days after committee stage

Any amendment can be made.

Amendments can be tabled as soon as committee stage has finished. Amendments tabled less than three sitting days before they are due to be considered may not be selected.

Any amendment can be made so long as it has not already been defeated during committee stage.

Amendments can be tabled as soon as committee stage has finished. They must be tabled at least two sitting days before they are due to be considered.

Commons

Immediately after report stage

Lords

At least three clear sitting days after report stage

Third reading is usually formulaic.

A ‘reasoned amendment’ to vote down the entire bill may be tabled, but these are rarely voted on.

Third reading is more substantive than in the Commons.

Amendments are limited to clarifying remaining uncertainties, improving drafting and following up earlier government undertakings. They must be tabled at least one sitting day before the stage.

Note: The intervals between parliamentary stages set out above represent standard practice for government bills, but can be departed from in some circumstances, including to ‘fast-track’ legislation. Intervals are usually longer for Private Members Bills.

How are amendments selected for debate?

In the Commons, the chair overseeing the debate plays an important role in deciding whether, and how, amendments are debated. Who occupies the chair varies depending on the parliamentary stage and how the bill is being considered.

During committee stage, the chair is either the Chairman of Ways and Means (the Principal Deputy Speaker) for proceedings on the floor of the House, or a chair from the Panel of Chairs (the group of MPs eligible to chair Public Bill Committees) for bills debated in a Public Bill Committee. The Speaker of the House of Commons selects amendments during report stage. The chair may group amendments together for debate. This is usually done by theme, to help structure the debate and avoid repetition.

Are there limits to what amendments can do?

The chair may refuse to select an amendment for debate if it is out of the ’scope’ of the bill, was submitted late, does not make sense, would make the bill unworkable or contradictory (a ‘wrecking amendment’), has been tabled to the wrong part of the bill or is vague. The chair must also reject an amendment that would involve spending money or raising taxes not previously authorised by the Commons in a financial resolution.

There is no selection of amendments in the Lords. This means that all published amendments can be debated. However, amendments may still be grouped for debate, by agreement between the Government Whips Office and the members who have tabled amendments. The clerks advise on whether amendments are within scope and the House ultimately decides.

How is the debate structured?

In the Commons, the time available for each parliamentary stage is usually determined by a programme motion proposed by the Government and agreed by the House after second reading. Programme motions are not used in the Lords.

Are all amendments voted on?

Many amendments are never formally moved or are moved but then withdrawn without a vote. This may be the case if MPs or Peers are satisfied with the Government’s rebuttal during the debate or if they have received assurances that concessions will be forthcoming. Other amendments may be withdrawn if they have little support. In the Commons, if the MP tabling the amendment does not move the amendment, it will not be voted on. In the Lords, an amendment may be moved by another Peer.

The Government may also accept amendments without the need for a vote.

After amendments are debated, and if they are not withdrawn or accepted by the Government, MPs or Lords will be asked to vote on whether an amendment should be accepted. Government drafting changes and other uncontroversial changes are usually agreed to without a formally recorded vote (known as a 'division').

What happens if a bill is amended?

If accepted, amendments are incorporated into the bill. However, the bill does not have legal effect until it is given Royal Assent and becomes an Act of Parliament. Any amendment incorporated into a bill may be modified or reversed during a later stage, either in the same House, or when it is considered by the other House (when the amended bill goes to the second House, it incorporates any amendments made by the first House).