“If a country cannot pass a law to save the lives of female cyclists — when that proposal is supported at every level of UK Government — then I don’t see how that country can truly be called independent.”

That’s what Boris Johnson wrote yesterday in his resignation letter.

But he’s wrong.

What have female cyclists got to do with Brexit?

Mr Johnson is known for his sometimes-tangential anecdotes — as anyone who remembers his speech at the 2008 Olympics, in which he claimed the British invented table tennis under the name “whiff whaff”, will tell you.

But we were still a little surprised to discover that this parting missive on the issue of Brexit — which he was apparently still writing when Number 10 confirmed his departure — spends a lot of time on vehicle regulation.

The former Foreign Secretary wrote: “we seem to have gone backwards since the last Chequers meeting in February, when I described my frustrations, as Mayor of London, in trying to protect cyclists from juggernauts.

“We had wanted to lower the cabin windows to improve visibility; and even though such designs were already on the market, and even though there had been a horrific spate of deaths, mainly of female cyclists, we were told we had to wait for the EU to legislate on the matter.”

His concluding thought on the issue: “If a country cannot pass a law to save the lives of female cyclists — when that proposal is supported at every level of UK Government — then I don’t see how that country can truly be called independent.”

“Supported at every level of UK Government”?

That’s quite a compelling account of how the EU has stifled common sense policy-making by a national government. The problem is, Mr Johnson is wrong.

It’s true that when he was Mayor of London, Mr Johnson campaigned to introduce tougher rules on lorry safety to protect cyclists.

But he’s left out some key details.

For one thing, he neglects to mention that the regulations he’s talking about were in fact put forward by the European Parliament, and backed by 570 MEPs, with 88 voting against. He also fails to acknowledge that those laws have actually been passed.

More crucially, Mr Johnson is wrong to say that the laws in question were “supported at every level of UK Government.”

When the regulations were put forward by the EU, the UK government explicitly did not support the proposals.

A government spokesperson told BBC News in 2014: “Where we are not supporting European Parliament proposals, it is simply because they will not produce practical changes in cab design and could lead to additional bureaucracy for Britain.”

The European Council, which includes representation from the UK government, later adopted the directive.

Mr Johnson should know he is wrong

It’s curious that Mr Johnson has chosen this particular example to demonstrate what he sees as the problems with EU regulation.

Not only did he know that the European Parliament had proposed the laws, he also knew that the UK government opposed them — because he explicitly called out ministers on the issue at the time.

In January 2014, Mr Johnson said: “If these amendments, supported by dozens of cities across Europe, can succeed, we can save literally hundreds of lives across the EU in years to come. I am deeply concerned at the position of the British Government and urge them to embrace this vital issue.”

Perhaps in his hasty drafting, Mr Johnson has misremembered the exact chain of events.

A source close to Mr Johnson told FactCheck: “Boris called for change more than a year before EU measures came into force. If we had taken back control we could have implemented them immediately in order to save lives.”