Control of the UK’s borders was central to the successful campaign to quit the EU, but the comments by four ambassadors to the broadcaster suggests a softer stance at odds with the Government in which he serves.
Johnson’s aides later insisted the Cabinet minister had been mis-interpreted, but Sky was standing by its story - insisting the ambassadors were speaking freely under Chatham House Rule, which allows them to be quoted but not named.
In any case, former Labour leader Ed Miliband blasted Johnson - who has admitted he wrote two columns before deciding to back Brexit, one for Leave and the other backing Remain.
Though fellow Brexit-eer Michael Gove was dismissive.
“(Boris Johnson) told us he was personally in favour of it, but he said that Britain had been more affected by free movement of people than other EU member states.”
“He did say he was personally in favour of free movement, as it corresponds to his own beliefs. But he said it wasn’t government policy.”
A third added:
“Boris Johnson has been openly telling us that he is personally in favour of free movement.”
And a fourth chimed in:
“Yes, he told us at an ambassadors’ luncheon.”
A spokesman for the Foreign Secretary said:
“Boris said what he has said many times before - he is pro-immigration but wants to take back control to limit numbers.
“He did not say he supported freedom of movement and challenges anyone to show proof that he ever said that.”
But aides later upped the ante: challenging Johnson’s accusers to “show proof that he ever said that”.
Earlier this month, Johnson declared that it is “bollocks” to suggest that EU citizens have an historic right to live anywhere across the European bloc.
The Foreign Secretary told a Czech newspaper that the freedom to move between states was not a founding principle of the European Economic Community.
In an interview with Hospodářské noviny, Johnson said:
“It’s a total myth - nonsense. It is stupid to say that freedom of movement is a fundamental right.
“The Brownian motion of people across Europe is not something that was in the founding Treaty of Rome in 1957, it was not in the Nice Treaty, and it was not in the Maastricht Treaty. It’s something that has been acquired by a series of decisions by the courts.”
He also prompted ridicule when he said the UK’s exit from the European Union will be a “Titanic success”. The Foreign Secretary drew comparisons to the ill-fated cruise liner, which sank when it crashed into an iceberg in 1912 on its maiden voyage, when presenting an award to George Osborne at the Spectator Parliamentarian of the Year Awards.