Julian Assange appeared in a British court Monday to fight extradition on espionage charges — with his attorney accusing the US of an extraordinary plot to “kidnap and harm” the WikiLeaks founder.

Assange, 48, had shaved his bushy white beard and raised a fist in defiance at supporters packed into Westminster Magistrates Court.

His lawyer, Mark Summers, accused the US of “intruding” on conversations between Assange and his lawyers while he was holed up in Ecuador’s embassy in London.

He even claimed there had been “hooded men breaking into offices” as part of “plans to kidnap and harm” Assange, according to Sky News.

Summers told the court he needed more time for the “mammoth” amount of preparation needed to fight Assange’s extradition to the US, where he faces an “unprecedented” case of espionage charges against a journalist.

However, Judge Vanessa Baraitser rejected the request to delay his extradition hearing, which currently is set for five days in February, Sky News said.

The case is expected to take months to resolve, with each side able to make several appeals of rulings.

US authorities accuse Assange of scheming with former Army intelligence analyst Chelsea Manning to hack a password for a classified government computer.

Assange, who earlier this year turned heads with his bushy David Letterman-style white beard, was instead clean-shaven and dressed in a blue sweater and sports jacket. He read his name to the court when asked and gave his date of birth.

The public gallery was jammed with Assange supporters, including former London Mayor Ken Livingstone, and outside the courthouse, others carried placards calling for Assange to be released.

Assange has been in Belmarsh Prison on the outskirts of London as the extradition case plays out. He is facing a number of serious charges, including espionage, but claims he is a journalist entitled to First Amendment protection.

With Post wires