Britain faces a tough challenge to retain global influence after its departure from the EU under a prime minister who has a well-known reputation for “lying”, France’s former ambassador to the UK said in an interview.

Sylvie Bermann, who was ambassador to London from 2014-2017 and witnessed the 2016 Brexit referendum at first hand, has raised some eyebrows in the UK with some decidedly undiplomatic comments in her book Goodbye Britannia published in French in January.

She professes her love for the “dynamic, traditional and modern” London, the squirrels and foxes in its parks and streets, British culture and the country’s sense of humour.

But in the book she also makes no attempt to hide a deep frustration with much of its political class and in particular those who led the country to Brexit, calling Prime Minister Boris Johnson an “unrepentant liar”.

“Why, when you are very dynamic and successful and influential in the EU, why do you decide to leave?” Bermann, who also served as ambassador to Moscow and Beijing, told AFP at her home in the heart of Paris.

“It will be more difficult. And there will need to be much more effort [by the UK] to have a true influence in the world.”

She said that this will be particularly hard in the geopolitical context of the “Cold War” between China and the US, with the two protagonists looking to the EU rather the UK.

“There is a triangular [China-EU-US] relationship and it is harder for the United Kingdom to play a role,” she said.

She said Britain’s much touted “special relationship” with the US “is above all special for the British” rather than the US.

“The United States often used the British as a bridge or relay with the EU. Obviously it is a role that is now lost.”

‘Bravo’

On top of this, there are difficulties in trade relations, as shown by Britain’s threat this week to break the terms of the Brexit withdrawal treaty by unilaterally delaying checks on food going to Northern Ireland.

“These are consequences of the choice made in the referendum,” she said.

Bermann acknowledged that in the fight against Covid-19, “the British vaccination campaign is better than the European one. Bravo for that” with far more people given the jab than in big EU member states.

But she added: “This is not totally due to Brexit as the vaccine orders were made while the UK was still subject to European rules.”