In exclusive interview, outgoing ambassador Sylvie Bermann says June vote has allowed diverse opinions to be heard.

The general election result was a game-changer that has paved the way for a “real debate” over Britain’s approach to leaving the EU, according to the outgoing French ambassador to the UK.

Sylvie Bermann suggested that the outcome of the vote, in which Theresa May lost her parliamentary majority, had opened the door to a wider variety of opinions and strengthened the voice of business.

In an exclusive interview with the Guardian to mark the end of a three-year term during a tumultuous period in British politics, the diplomat described watching the election results with people from the Labour party, the Tories and the Liberal Democrats.

“Everybody said that Theresa May would have between a 30- and 80-seat majority and when we watched the TV everybody was surprised: the reaction was that the results of these elections were a game-changer,” she said.

“Now you hear more diverse opinions about Brexit, more views from the business community. I think it is a good thing when you have a real debate – it is democracy.”

Asked if she believed those conversations about Britain’s approach to Brexit were lacking before the June poll, she added: “Well yes, there was no debate before the election.”

Bermann, who has made clear that she is sad about Brexit and believes both Britain and the EU would have been better off without it, expressed some disappointment with the tone of the referendum campaign. “Generally speaking this scaremongering about immigration was exaggerated,” she said.

She said there had been “lots of comments” over the BBC’s role in the campaign, given the legal necessity for the broadcaster to balance its output during an election.

“Well, it was kind of a false neutrality – because everybody was supposed to be equal even if you had good experts on one side, and some not so much expert on the other side,” she said, adding that she saw the BBC as Britain’s “soft power” with huge influence across the world.

The diplomat said it was not for her to judge whether the result had placed Britain more on track towards a more sensible form of Brexit, but said she did believe it had resulted in a “reality check”.

Bermann acknowledged that June’s hung parliament, after a race in which the prime minister had demanded a mandate for Brexit, had emboldened advocates of soft Brexit including the chancellor, Philip Hammond – whose outspoken interventions in recent days have frustrated some ardent leave campaigners.

Asked if she was pleased to see Hammond’s voice amplified, Bermann started by insisting that it was a domestic issue, before adding: “But I think he is a very wise man, and he is a very knowledgable man.”

When asked about the UK’s leave-supporting foreign secretary, she laughed and said: “I like Boris Johnson. It is not about Brexit – he was very supportive as mayor of London and he was the one who decided to illuminate Trafalgar square with the Tricolore,” she said, referring to London’s tribute to France after the 2015 Paris attacks.

Speaking in the grand back room of the French ambassador’s residence in west London, with large windows overlooking a beautiful garden behind with the immediate backdrop of Hyde Park, she laughed at the UK’s obsession with its departure from the EU.

“Brexit in the morning, Brexit for lunch and Brexit for dinner,” said Bermann, smiling as she described an ambassador’s life of politically soaked meetings from morning until night.

There was nothing like the same focus on the issue over on the continent, she said, adding: “It is not the case in France or in Europe – the priority in the EU is to protect and strengthen the EU and to deal with migration crisis. Brexit is not a priority for us.”

For France and Britain, she stressed the need for ongoing defence cooperation whatever happened in EU negotiations, referencing a joint plan discussed by May and Emmanuel Macron when they met in Paris and the French president took the prime minister to a football match.

The ambassador said the election of Macron had made French people “more optimistic” and boosted respect for the country across the world.

His outspoken stance on climate change and international trade at the G20 summit in Hamburg had, she argued, opened up the space for Macron to invite Donald Trump to his country without triggering anger among French voters.

“You need to be strong internally to be able to have a strong diplomacy and I think that Emmanuel Macron was very firm with Donald Trump and that is why he was also able to invite him to Bastille Day [in Paris],” she said, pointing also to the meeting between Macron and Vladimir Putin.

“For the time being it is probably easier for France to have a complete relationship with the US,” added Bermann, saying that a Trump visit in Britain would trigger protests.

Bermann said she had enjoyed her time in the UK. “I love the way of life, this dynamic city, the parks and trees, the foxes in city gardens – they are quite exotic for us! – the theatre and cultural life, and the sense of humour.”

The ambassador then pulled out a book, Alice in Brexitland, with a picture of the grinning face of Nigel Farage on the body of a ginger cat, pint in hand. Under the title were the words: “You don’t have to be mad to live here but it helps.”

And with that, Bermann burst – once again – into laughter.