He was criticised by the Iraq Inquiry for providing unverified intelligence about weapons of mass destruction to the Prime Minister, Tony Blair.

[16] He is also a "senior advisor" to the Monitor Group – a consultancy and private equity firm which has been implicated in undertaking PR work for Libya and Muammar Gaddafi.

"[21]: 11:50 In 2012, Dearlove took a sabbatical from Cambridge University to write an account of events leading up to the 2003 invasion of Iraq from his perspective at MI6, including coverage of the production of the so-called "dodgy dossier".

[27] He stated further that foreign mass migration's geopolitical impact upon Europe, if it was not prevented, was set to reshape its political landscape as those of its citizens who feel their interests are threatened asserted their influence.

[28] On 8 June 2017, Dearlove intervened on the day of the 2017 UK general election in The Daily Telegraph saying "how profoundly dangerous it would be for the nation if Jeremy Corbyn becomes Prime Minister.

"[29] On 29 November 2018 Dearlove co-signed an open letter, published in a British national newspaper, condemning Prime Minister Theresa May's negotiated Brexit withdrawal agreement after the 2016 Referendum on the issue, as the matter was passing through the House of Commons to be voted upon.

[31] In early December 2018 Dearlove, in a jointly authored text with Major-General Julian Thompson, published on the website 'Briefings for Brexit' an extensive reply to May's statement entitled 'The Prime Minister is misleading the country on defence and security', citing a 'worryingly poor understanding of the issues' by her office.

[32] On 8 January 2019, Dearlove sent a letter co-signed by Field Marshal Lord Guthrie to all Chairs of Conservative Party Parliamentary Constituency Associations with sitting Members of Parliament stating that the passage through the House of Commons of the Brexit withdrawal agreement contained decisions which fundamentally undermined the integrity of the Defence of the Realm, and requested that they take measures to discourage their parliamentary representatives from voting for it in the Commons.

The letter as an alternative advocated the case upon national security grounds that the United Kingdom should fully withdraw from the European Union without an Intergovernmental relationship between the two persisting after the process.

[33][34] On 16 May 2019 Dearlove characterised Huawei's role in the British 5G network as "an unnecessary risk" as it could give the Chinese government a "potentially advantageous exploitative position".