[7] They aim to secure better outcomes for the UK by seeking improvements to the UK-EU relationship, advocating evidence-based policy recommendations to decision makers.

[19] Following the 2019 European elections Best for Britain launched a campaign and petition that called for the leaders of political parties that supported remaining in the EU to work together to achieve that goal.

On 23 June 2018 Best for Britain supported and participated in the People's Vote march in London to mark the second anniversary of the referendum to leave the European Union.

[35] Best for Britain coupled this manifesto launch with the stated intention to campaign in around 70 key marginal seats, trying to persuade both Labour and Conservative MPs to support a second referendum.

The campaign slogan, displayed on billboards and in newspaper ads in Birmingham, Carlisle, Manchester, Liverpool, London and Stoke [35] was: "We all deserve a final say on the Brexit deal.

... We will support candidates who campaign for a real final vote on Brexit, including rejecting any deal that leaves Britain worse off.

Miller left Best for Britain after the 2017 election,[42][43] expressing concern that the group had become more anti-Tory than Brexit-focused and described it as "a room full of white males deciding what's going to happen to the country"[43] and as "undemocratic".

[46] A letter was sent to Chancellor Rishi Sunak in February 2021 by a group of 60 MPs calling on the government to consider support proposals drawn up by tax expert Rebecca Seely Harris.

[49] When asked if this would be a replacement for the select committee on the Future Relationship with the European Union previously led by Hilary Benn he said that it would have an “intensely practical focus” on the problems being faced by business.

[51][52] The Telegraph's report was described as an "antisemitic dogwhistle"[53] and also criticised for calling Best for Britain's public aim to stop Brexit a "secret plot".