Former Vice President Joe Biden on Saturday night scrambled the name of the British Prime Minister Theresa May with Margaret Thatcher – who left office in 1990.

Biden, 76, made his gaffe at a fundraising rally in Columbia, South Carolina. While searching for the name of the UK’s current leader, the Daily Express reports he said:

“Margaret Thatcher um, excuse me, Margaret Thatcher – Freudian slip,” Mr. Biden said to growing laughter. “But I knew her too.” He then corrected himself: “The prime minister of Great Britain, Theresa May”

He invoked Mrs. Thatcher’s name when telling donors he had heard from 14 heads of state from around the world – not one of which he named – who’ve voiced concerns to him about President Trump.

That list included Mrs. Thatcher, he alleged, before correcting the “Freudian slip,” saying he was referring to May.

The U.K. head of state is Queen Elizabeth II, not the prime minister.

The presidential aspirant went on to claim without evidence Mrs May had called him out of concern about U.S. President Donald Trump.

He said Mrs May had asked him: “We still have a special relationship between the United States and England?

“I said, jokingly, ‘It’s an Irishman telling you, yeah.”

This is not the first time UK politics and Mr. Biden, who is running for president for the third time since 1988, have intersected on the campaign trail.

His first campaign was hugely criticised after it was found an address had been lifted from Neil Kinnock, then UK Labour leader who was running against Mrs Thatcher at the time.