At the
2005 general election, Cartlidge contested
Lewisham Deptford as the
Conservative candidate, coming third with 12.4% of the vote behind the incumbent
Labour MP
Joan Ruddock and the
Liberal Democrat candidate
Columba Blango.
1st term (2015–2017) Cartlidge was elected to Parliament at the
2015 general election as
MP for
South Suffolk with 53.1% of the vote and a majority of 17,545. In July 2015, in one of his first actions in Parliament, Cartlidge brought a barrel of local beer from his
constituency into the
House of Commons to drink with his new parliamentary colleagues. Also in July 2015, Cartlidge took a train journey from
Sudbury to
Marks Tey with rail executives from
Abellio Greater Anglia,
Network Rail and officials from the
Department for Transport to highlight issues affecting those travelling by train to his constituency. In November 2015, he held a
South Suffolk Food Day in the Commons featuring businesses such as
Jimmy's Farm, Suffolk Food Hall and Gifford's Hall Vineyard. Cartlidge has worked to improve mobile phone signal in his constituency: in February 2016 he launched a campaign in
Boxford for greater efforts to provide mobile telephone coverage in 'not-spots'. Cartlidge was elected to serve on the
Public Accounts Commission in November 2015 and the
Work and Pensions Committee in October 2016. He was opposed to
Brexit prior to the
2016 referendum.
2nd term (2017–2019) At the snap
2017 general election, Cartlidge was returned as MP for South Suffolk with an increased vote share of 60.5% and an increased majority of 17,749. In January 2018 he was appointed as
PPS to
Health Secretary,
Jeremy Hunt, and remained his PPS when Hunt was promoted
Foreign Secretary. In July 2019 Cartlidge was one of 73 MPs to vote against
equal marriage in Northern Ireland. He has publicly expressed his strong support for equal marriage but voted against imposing this law in Northern Ireland 'in absentia'.
3rd term (2019–2024) Cartlidge was again re-elected at the
2019 general election with an increased vote share of 62.2% and an increased majority of 22,897. In October 2020, Cartlidge wrote in the
East Anglian Daily Times that
COVID-19 exacerbated the need for part-time season rail tickets. On 17 September 2021, Cartlidge was appointed
Parliamentary Under-Secretary of State for Justice and an
Assistant Government Whip in the
Cabinet reshuffle. During his time in office, he introduced the
Statutory Instrument which raised
magistrates' sentencing powers in England and Wales from 6 to 12 months. Cartlidge also delivered the Government's initial response to the Criminal Legal Aid Independent Review, which resulted in most criminal
legal aid fees being increased by 15%. On 7 July 2022, Cartlidge resigned from HMG in the wake of widespread criticism of
Boris Johnson's mishandling of the
Chris Pincher scandal, which precipitated a large number of
ministerial resignations. Cartlidge served as
Exchequer Secretary to the Treasury from 28 October 2022 to 21 April 2023. On his last day in office, he oversaw clauses of the
Finance Bill introducing a new lower rate of
alcohol duty specifically for draught beer and cider. He replaced
Alex Chalk as
Minister of State for Defence Procurement in April 2023, following a mini-reshuffle. On 22 February 2024, Cartlidge launched the
Defence Drone Strategy, committing the
Ministry of Defence to its first comprehensive capability plan for uncrewed systems. On 28 February 2024, in a Commons Oral Statement he set out plans to overhaul defence acquisition, introducing a new
Integrated Procurement Model.
4th term (2024–) At the
2024 general election, Cartlidge was again re-elected, but with a decreased vote share of 33% and a decreased majority of 3,047. Following the Conservative Party's defeat at the general election, and the subsequent formation of the
Starmer ministry, Cartlidge was appointed
Shadow Defence Secretary in
Rishi Sunak's caretaker Shadow Cabinet. He retained this post upon
Kemi Badenoch's election as
Conservative Party Leader. In April 2025 he visited
Ukraine and had talks with senior officials. ==Personal life==