After the 2017 general election which Baker was reelected in, he was appointed Parliamentary Under-Secretary of State for Exiting the European Union under Prime Minister Theresa May.

After serving in parliament for 14 years, Baker was defeated at the 2024 general election; losing his seat to the Labour Party.

[17][18] In March 2011, Baker initiated an adjournment debate alleging a malicious prosecution of an operator of an independent mental health unit.

[19] That year, Baker attracted controversy after he was one of three Conservative MPs who went on a luxury trip to Equatorial Guinea, funded by the Government of the state, via a trust based in Malta.

In 2010, in a series of parliamentary questions, Baker asked the Work and Pensions Secretary: "If he will bring forward proposals to distinguish the white form of asbestos and the blue and brown forms of that substance", also questioning: "If he will commission an inquiry into the appropriateness of the health and safety precautions in force in respect of asbestos cement.

[32] In February 2018, as a minister in the Department for Exiting the European Union, Baker was forced to apologise after inaccurately claiming that civil servants had deliberately produced negative economic models to influence policy.

Answering questions in the House of Commons, Baker confirmed a claim by the Eurosceptic backbencher Jacob Rees-Mogg that Charles Grant, the Director of the Centre for European Reform, had reported that Treasury officials "had deliberately developed a model to show that all options other than staying in the customs union were bad, and that officials intended to use this to influence policy".

By the time the audio was released by Prospect magazine, the Prime Minister's spokesman had already backed Baker's claims.

[36][37][38][39] On 22 October 2018, Baker submitted a letter of no confidence in Theresa May's leadership over her Brexit Withdrawal Agreement proposals, stating that he had become convinced it was not possible to "separate the person from the policy.

[46] The Telegraph described them as being seen by Westminster as an "echo" of the Brexiteer ERG, and a response by backbench Conservatives to Nigel Farage's anti-lockdown Reform UK party.

[49] He said this two days after he had praised the prime minister's new apology given that week for his actions during the period of behaviour restrictions imposed over the COVID pandemic.

[50] Following the resignation of Johnson in July, Baker considered a possible candidacy to succeed him,[51] but ultimately chose not to stand and endorsed Suella Braverman.

[55] Baker endorsed Rishi Sunak in the October 2022 Conservative Party leadership election and was subsequently reappointed as Minister of State for Northern Ireland.

[56] He was appointed Minister of State for the Cabinet Office in February 2024, with the responsibility for carrying through the implementation of the Windsor Framework.

[68] He was a trustee of the Global Warming Policy Foundation from May 2021 to September 2022,[69][70] an organisation which has historically breached Charity Commission rules on impartiality in its climate change coverage.

[72] Baker has said he would end incentives for wind and solar power because "they are fundamentally intermittent sources of energy", and instead would encourage domestic production of natural gas.

He said many green measures including farmers' support payments were "anti-human life on Earth in the name of environmentalism", and would encourage maximising food production.

[76] Back in 2010, he stated at a meeting of the Libertarian Alliance that he thought "the European Union needs to be wholly torn down", considering it "an obstacle to ... free trade and peace among all the nations of Europe as well as the world".

[77] Baker argues Brexit presents an opportunity for more free trade outside the EU but also favours protectionism against China.

He argued that the current situation risks infringing both the freedoms of the religious and LGBT communities, and that private individuals should define the term marriage, rather than the state.

[83] In February 2021, Baker proposed to reform the Public Health Act legislation to "prevent ministers [from] imposing job-destroying restrictions without warning or scrutiny" in light of the COVID-19 pandemic in the United Kingdom, to ensure that economists have a share of seats on the advisory board where "decisions on social restrictions are made", and drew inspiration for his proposed monthly sunset clauses from the Civil Contingencies Act.