European Commission president Jean-Claude Juncker has accused Boris Johnson of talking "total nonsense" for suggesting he is seeking to create a European superstate.
His comments came as he answered questions at a press conference in Brussels taking place as the Foreign Secretary made a high-profile speech on Brexit in London.
The Commission president was asked to respond to Mr Johnson's suggestions that he was trying to turn the EU into a federal superstate.
Mr Juncker replied: "Some in the British political society are against the truth, pretending that I am a stupid, stubborn federalist, that I am in favour of a European superstate.
"I am strictly against a European superstate. We are not the United States of America, we are the European Union, which is a rich body because we have these 27, or 28, nations.
"The European Union cannot be built against the European nations, so this is total nonsense."
In the run-up to 2016's Brexit vote, Mr Johnson sparked a row after suggesting the EU was seeking to build a superstate comparable to that envisaged by Hitler during Nazi-era Germany.
"Napoleon, Hitler, various people tried this out, and it ends tragically. The EU is an attempt to do this by different methods," he said at the time.
In his speech in London today, Mr Johnson sought to quell fears expressed by companies and Cabinet members that exporters would be cut out of their biggest market of 500 million European customers.
Today’s address, called Uniting For A Great Britain,is the first of five from Cabinet ministers in an unprecedented public battle over policy.
Read More
Mr Johnson mocked fears that Brexit would mean “some autarkic 1950s menu of spam and cabbage and liver” or a “great V-sign from the cliffs of Dover”.
But he warned it would be "mad" to end up with a Brexit settlement that does not allow the UK to enjoy the "economic freedoms" of leaving the European Union.
