The imprisoned Wikileaks founder Julian Assange is not allowed to go to the highest British court in the legal dispute over his extradition to the United States.

According to the British news agency PA, the Supreme Court in London announced on Monday that it had rejected the application by Assange's lawyers.

The reason given by the court was that there were insufficient legal grounds for this.

A possible extradition to the USA has thus become more likely.

The US judiciary wants to put Assange on trial for allegations of espionage.

The native Australian faces up to 175 years in prison if convicted.

He is accused of having stolen and published secret material from US military operations in Iraq and Afghanistan together with whistleblower Chelsea Manning, thereby endangering the lives of US informants.

Extradition initially prohibited due to poor health

His supporters, on the other hand, see him as an investigative journalist who brought war crimes to light and who should now be made an example of.

The 50-year-old has been held in Belmarsh high-security prison in London for around three years.

A British court in the first instance prohibited Assange's extradition in early 2021 due to his mental health.

The judge argued at the time that the expected prison conditions would otherwise drive the mentally unstable Assange to suicide.

Otherwise, she found the extradition request to be justified.

In the appeal process, Washington then presented assurances that Assange would be treated humanely in US prisons - and was successful in doing so at the end of last year: the High Court gave the green light for extradition.

Assange wanted the Supreme Court to review this decision, which the High Court at least allowed, but the highest court has now rejected.

The legal tug-of-war by the British authorities has been dragging on for a long time.

In the event of Assange's final defeat in court, the British Home Office would have to decide whether to extradite him to the United States.

This step should have come a little closer with the latest decision.

The Wikileaks disclosure platform published a statement from Assange's lawyers in which they explain what course they now expect.

The case will therefore be referred back to Westminster Magistrates' Court, which ruled first in the case.

This will probably refer the decision on the extradition to the Ministry of the Interior, it said.

According to their own statements, the defenders could still bring their point of view there.

Further objections are also possible.

On March 23, Assange plans to marry his fiancée Stella Moris in Belmarsh maximum security prison.

Their two sons are said to be present at the ceremony.