Conservative party factions

One Nation caucus

• The largest single group within the parliamentary party says more than 100 Conservative MPs are members, almost a third of the total.

• The phrase, "one-nation Tory", goes back to 19th-century Prime Minister Benjamin Disraeli, but the caucus was formed only in 2019.

• Chaired by former First Secretary of State Damian Green, it says it is "committed to the values of the liberal centre right".

• Many of its members represent traditionally Tory "blue wall" seats where the Liberal Democrats are the main challengers.

European Research Group

• Once the most powerful grouping of Tory MPs, the ERG played a key role in blocking Theresa May's Brexit deal and then bringing her down as prime minister, which paved the way for successor Boris Johnson to strike a harder Brexit.

• It does not publish information about its membership, but this is currently thought to be in the 30s, significantly down on its Brexit heyday.

• Example members include Jacob Rees-Mogg ans Suella Braverman 

• Represents strong stance on immigration

The New Conservatives

• Formed only in May 2023, the New Conservatives have fast become one of the most vocal factions within the party.

  Around 30 MPs are members, including deputy Tory chairman Lee Anderson, and group co-chairs Miriam Cates and Danny Kruger.

• Most were elected in 2019, many in marginal, traditionally Labour, "red wall" seats in the north of England and the Midlands.

• The New Conservatives have called for radical measures to cut migration and pressed the government to deliver deportations to Rwanda by "unpicking" many of the UK's international obligations.

• Ms Cates and Mr Kruger were among the 29 Tories who refused to back the Rwanda bill in the Commons.

• On broader policy, the group says the party needs to return its 2019 manifesto by delivering levelling up and reducing taxes, rein back on green measures, and ban "gender ideology" in schools

Common Sense Group

• Launched in 2020 and with around 30 members, the CSG is led by former Home Office minister Sir John Hayes, a close ally of Suella Braverman.

• Like Mrs Braverman, Sir John has been fiercely critical of Mr Sunak's Rwanda approach and, alongside the New Conservatives, the group has been pressing for tougher action on both illegal and legal migration.

• It has also pushed hard on culture issues, such as Mr Sunak's plans to phase out smoking, other manifestations of what it regards as "the nanny state", and what it described as the National Trust's "woke agenda" on colonialism

Northern Research Group

• Thought to number more than 50 MPs, the group was formed in 2019 to press for greater investment in "red wall" areas in the north of England, Wales and the Scottish borders.

• Senior figures include former party chairman and Northern Powerhouse minister Sir Jake Berry, former Brexit Secretary David Davis, and Esther McVey.

• The NRG regards immigration as an important issue for many of its MPs' voters.

Conservative Growth Group

• Around 50 MPs are thought to be members of a group set up in the aftermath of Liz Truss's disastrous, short tenure at No 10.

• Its focus is chiefly economic: it advocates the libertarian policies it believes Ms Truss was prevented from introducing by the unravelling of her mini-budget in September-October 2022.

• It says the policies needed to break out of a long period of low growth include slashing business taxes and stamp duty, toughening benefit requirements, relaxing planning, and reintroducing fracking