Julian Assange has been told to stop using the Ecuadorean embassy in London to poke fun at Australian politicians as part of his Senate election bid, it has been reported.

The South American nation's president, Rafael Correa, chastised Assange after a video appeared online in which the WikiLeaks founder – along with Juice Rap News – ridiculed Tony Abbott, Kevin Rudd and Julia Gillard.

"We have sent him a letter: he can campaign politically, but without making fun of Australian politicians. We are not going to allow that," said Correa, who is attending a South American summit in the Surinamese capital Paramaribo.

Assange appeared wearing a comedy wig and bandanna emblazoned with the Australian flag in the video. He also performed a cover version of John Farnham's You're the Voice.

He is one of six WikiLeaks party candidates running for election. The party's chances at the ballot box were hit when Assange's running mate in Victoria, Leslie Cannold, resigned. She was followed out of the door by six other members.

Tensions between Assange and his Ecuadorean hosts were heightened during the Snowden affair, with diplomats saying that they felt that the WikiLeaks founder was trying to steal the limelight.

According to Agence France-Presse, Correa said: "The rules of asylum in principle forbid meddling in the politics of the country that grants asylum. But as a matter of courtesy, we are not going to bar Julian Assange from exercising his right to be a candidate. Just so long as he doesn't make fun of Australian politicians or people."

Assange took refuge in the Ecuadorean embassy in London in June 2012 to avoid extradition to Sweden, where he is wanted for questioning about sexual assault allegations.

He fears Sweden would extradite him to the United States, where he believes he is wanted in relation to WikiLeaks' disclosure of a huge trove of classified US military and diplomatic documents.

Chelsea Manning, the US army private who leaked the documents to Assange's organisation, was sentenced to 35 years in prison by a US military court on 21 August.

• This article was amended on 2 September 2013. An earlier version referred to the capital of Suriname as Paramarimbo rather than Paramaribo.