Assange's US extradition appeal to be heard in July

WikiLeaks founder Julian Assange's appeal against extradition from Britain to the United States will be heard in July, court officials in London say.

The Australian-born Assange, 52, is fighting extradition to the US where he is wanted on 18 charges, nearly all under the Espionage Act, relating to WikiLeaks' mass release of secret US documents - the largest security breaches of their kind in US military history.

In May, the High Court in London granted him permission for an appeal over his argument that he might not be able to rely on his right to free speech at a trial in a US court.

That appeal will now be held on July 9-10, a spokesperson for Britain's Judicial Office said on Tuesday.