Hybrid bills

One option governments can use to get large-scale infrastructure projects off the ground – such as new rail networks or expanding airports – is the hybrid bill process.

What is a hybrid bill?

Most bills that pass through parliament are ‘public bills’, which means they apply to the general population. Others are ‘private’, where the legislation affects only a specific individual or corporation. Hybrid bills contain aspects of both: the legislative changes they propose affects the general public but will also have a direct impact on specific individuals, groups or areas.

The High Speed Rail project (HS2) was launched by a hybrid bill because it benefits the wider public but has a specific impact on people who live along its route – if for example their property is in the direct line of the railway and they face compulsory purchase. Most recent hybrid bills focus on largescale infrastructure projects (Crossrail being another example) but hybrid bills do not have to be ‘works bills’, as was the case with the hybrid Holocaust Memorial Bill which became an Act in January 2026.

If a public bill is thought to affect private interests, a group of parliamentary officials known as the ‘examiners of petitions for private bills’ determine whether it is hybrid. Hybrid bills are subject to a different parliamentary process to ensure that those private interests are properly considered – determining that a bill has hybridity will alter the process and can add on significant time to the legislative process.

How do hybrid bills proceed through parliament?

If a bill introduced into the Commons or Lords is deemed hybrid, the examiners will make sure that the bill complies with relevant standing orders, which can include requirements to give notice of the bill’s proposals in newspapers and identifying those affected. An environmental statement is also required if the bill authorises the acquisition of land. Before the bill proceeds to the second reading, members of the public can comment on the environmental impact statement.

Like a public bill, a hybrid bill is debated at second reading, but then instead of progressing to a bill committee or ‘committee of the whole house’ a hybrid bill is assigned to a specially formed select committee. Membership is usually chosen by the whips and committee members must have no conflicts of interest – using the rail example, this might be if they represent a constituency along the proposed route.

At this stage, hybrid bills are subject to petitioning, where any individuals, groups or organisations who are directly affected can petition the committee. The committee hears those objections and the replies from the bill’s promoters, and can then make amendments to the bill or require the promoter to give commitments to petitioners to address their concerns.

During this committee stage the promoter can bring ‘additional provisions’ to the bill. These can be major alterations to the original proposals outlined at second reading – for example, an additional provision for the first HS2 hybrid bill saw the deep-bored tunnel in the Chilterns extended by 2.6km. ²¹ High Speed Two Limited, High Speed Two Phase 2ª Information Paper: Additional provisions, HS2 Limited, High Speed Rail (London-West Midlands) Bill: Special report of session 2016-17 (HL Paper 83), The Stationary Office, 2016.

These additional provisions have been described as ‘mini hybrid bills in their own right’. They can add significant time onto the process as they may require a further environmental impact statement and trigger a fresh petitioning period. ²² House of Lords Committee on the High Speed Rail (West Midlands-Crewe) Bill, High Speed Rail (West Midlands- Crewe Bill): Special report of session 2019-21 (HL Paper 149), The Stationary Office, 2020.  After the committee has reported, it follows the same path as other public bills: committee stage (usually a public bill committee in the Commons, or a committee of the whole house, or grand committee in the Lords), report stage and third reading.

The bill must also progress through the other chamber where a further petitioning and special committee consideration takes place – though additional provisions cannot be deposited in the second house.

How long do hybrid bills take to pass through parliament?

Hybrid bills take a long time to pass into law and are often carried over between parliaments. The Holocaust Memorial Act – which facilitates the construction of a memorial and a learning centre in Victoria Tower Gardens, near parliament – was introduced as a bill in February 2023 and carried over after the July 2024 general election. It received Royal Assent in January 2026. ²⁶ UK Parliament, ‘Holocaust Memorial Bill’, retrieved 16 July 2025, https://bills.parliament.uk/bills/3421/stages

The added procedural steps can lengthen the time it takes to progress the bill. Requirements for an environmental impact statement for example add – at a minimum – 98 days before the bill progresses to second reading. ²⁷ 56 days for public consultation; 28 days for assessor on receipt of comments; 14 further days before second reading.

Depending on the volume of petitioning, the bill can be delayed for years at the committee stage in the first house. The first of the HS2 hybrid bills spent nearly two years in the hybrid bill committee stage alone.

How often are hybrid bills used?

Hybrid bills are rare. Since 1979, only 15 have received royal assent. ²⁸ Searle, C and Coleman, C, ‘Hybrid bills receiving royal assent since 1979’, House of Commons Library, 26 September 2023, retrieved 16 July 2025, https://commonslibrary.parliament.uk/research-briefings/sn05279  There is currently just one before parliament.
 

What kinds of proposals become hybrid bills?

Hybrid bills may be used for major infrastructure projects of national importance – such as the construction of national railways (HS2). They can be an attractive option to government for such projects because they can grant more extensive planning powers and the process allows for alterations to the initial project (by bringing forward additional provisions to a scheme). Projects that go through the hybrid bill process are also insulated from some kinds of judicial review.

All bills are checked for potential hybridity upon introduction and while the government can usually anticipate if a bill will be hybrid, a surprise designation can upset the government’s planned legislative timescale (as happened with the Holocaust Memorial Act). ³³ House of Commons Examiners of Petitions for Private Bills, Holocaust Memorial Bill: Report from the Examiners and Statement of Reasons Session 2022–23 (HC 1403), The Stationary Office, 2023.

Where else are hybrid bills used?

The devolved governments all have provisions for hybrid bills. ³⁴ Welsh Parliament, Standing Orders of the Welsh Parliament, January 2025, retrieved 16 July 2025, https://senedd.wales/media/n33df5ry/so-eng.pdf. Northern Ireland Assembly, Standing Orders of the Northern Ireland Assembly, retrieved 16 July 2025, https://www.niassembly.gov.uk/assembly-business/standing-orders/. The Scottish Parliament, ‘Standing Orders of the Scottish Parliament’, retrieved 16 July 2025, https://www.parliament.scot/about/how-parliament-works/parliament-rules-and-guidance/standing-orders.  The only hybrid bill to have been taken before the Scottish parliament was the Forth Crossing Bill – which provided powers to construct a new crossing over the Firth of Forth. It was introduced in November 2009 and was enacted in January 2011.

Hybrid bills are used in Singapore, such as for the Cross-Border Railways Act 2018, which laid the groundwork for the construction of railways between Singapore and Malaysia. ³⁵ Republic of Singapore, Cross-Border Railways Act 2018.  The Republic of Ireland has provisions for hybrid bills, but such a bill has not been brought forward in recent history. ³⁶ McCaffrey, R, ’Provision for hybrid bills in other legislatures’, Northern Ireland Assembly, 19 January 2016, retrieved 16 July 2025, https://www.niassembly.gov.uk/globalassets/documents/raise/publications/2016-2021/2017/procedures/0617.pdf  Other Westminster systems – Canada, Australia and New Zealand – do not have hybrid bills.