Brexit: How Britain was out-negotiated

Jon Danzig | 25 September 2025

Michel Barnier, the EU’s chief Brexit negotiator, kept a secret diary of the talks.

Published in 2021, it revealed in painful detail why Britain lost so badly at the negotiating table. Jonathan Powell, former Downing Street chief of staff, summed it up. Britain was left with:

“a flawed withdrawal agreement and a deeply disadvantageous future relationship, both of which will cause us major problems for decades to come.”

Barnier’s account highlights five key reasons.

1. Prepared vs unprepared: Barnier mastered every detail. Britain’s first Brexit Secretary, David Davis, turned up empty-handed. Barnier was shocked by his “nonchalant” approach.

2. EU unity: The EU27 stood together. Britain tried to bypass Barnier by approaching individual states, but was repeatedly sent back to him.

3. Clarity vs chaos: The EU knew what it wanted. Britain was consumed by internal arguments. Barnier wrote that Theresa May spent more time negotiating with her own ministers than with Brussels.

4. Johnson’s failed “mad man” strategy: Attempts to provoke or threaten the EU backfired. In 2020 David Frost cancelled talks, then humiliatingly returned a week later.

5. The deadline trap: Theresa May triggered Article 50 without a plan. Boris Johnson agreed to a border in the Irish Sea despite knowing what it meant. At one point Barnier had to explain to MPs that “the health of cows cannot be checked by drone.”

Barnier’s diary makes one thing clear. Britain was out-negotiated at every turn. And the consequences are still with us. Britain and Britons were far better off when we were in the EU.

We had full access to the world’s largest single market.
We had a seat at the table shaping the rules.
We enjoyed freedoms and protections now lost, from cheaper food and travel to stronger rights at work.

Some Leave voters now say they did not get the Brexit they wanted. But nobody voted for a version of Brexit. That was not on the ballot paper. People who voted Leave could not know what they would get.

Now many of them, along with most of the country, regret the reality we ended up with.

As Jonathan Powell concluded, there should have been an inquiry into why Britain, once so proud of its diplomacy, was so utterly defeated.

Barnier’s diary may be the closest we will get.