Guillermo Lasso has warned he will evict Julian Assange from the Ecuadorian embassy
Mr Assange has been holed up in his embassy sanctuary since 2012 after being faced with extradition charges relating to a sexual assault claim in Switzerland.
Mr Lasso said he would give Mr Assange just 30 days’ notice to leave the embassy and face UK police.
He said hosting the Wikileaks chief was becoming too expensive for Ecuador’s taxpayers and it was time to end the arrangement.
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We will cordially ask Señor Assange to leave within 30 days of assuming a mandate
The right-wing presidential candidate said: “The Ecuadorian people have been paying a cost that we should not have to bear.
“We will cordially ask Señor Assange to leave within 30 days of assuming a mandate.”
Ecuadorian foreign minister Guillaume Long said the media attention and security pressure involved with hosting Mr Assange was proving too much to bear.
Protestors calling for Mr Assange's extradition charges to be dropped
He said: “Our staff have been through a lot. There is a human cost.
“This is probably the most watched embassy on the planet.
“It’s a very precarious position. In terms of his physical comfort we have done all we can. But there is no access to an outside space. There is no patio or garden so he has mostly spent four and a half years on the first floor of a building in London, where there is not much light, especially in winter.”
Facts about WikiLeaks founder, Julian Assange Mon, August 22, 2016
WikiLeaks Founder, Julian Assange has led a very interesting and controversial life which has been at the centre of global debate
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It is believed that Julian Assange chooses to live in Sweden because the country's media laws are among the world's most protective for journalists
Mr Assange may not need to panic just yet, however, as Mr Lasso is still some seven points behind the ruling party candidate Lenin Moreno in opinion polls.
Last month, Barack Obama used one of his last acts as President of the United States to grant whistleblower Chelsea Manning clemency.
This was seen as a way to force Mr Assange to leave the building, after he previously promised to do so if Ms Manning was granted justice.
Julian Assange has been holed up in London's Ecuadorian embassy since 2012
Julian Assange has been threatened with eviction by Guillermo Lasso
Following the granting of clemency, Mr Assange said Mr Obama was only doing it to “make life hard” for him.
Channelling Mr Obama’s thought process, Mr Assange said: “What’s the result? It is going to make life hard for Assange because either he will be extradited to the US or we will show him [as] a liar. Therefore, it is OK to pardon Chelsea Manning. That’s what happened.”
It remains uncertain whether Mr Assange will leave on his own accord in the near-future.
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