WikiLeaks smear effort to reveal Swedish FM Carl Bildt as US 'spy'.

WikiLeaks is planning a smear campaign against Sweden to halt the extradition of founder Julian Assange to the United States, including releasing documents allegedly showing that Swedish foreign minister Carl Bildt has acted as an informant for the United States since the 1970s.

According to an internal WikiLeaks memo reviewed by Swedish tabloid Expressen, WikiLeaks plans to release more classified documents, organize blockades of Swedish embassies and consulates as well as boycotts of Swedish companies.

“This is going to hurt Sweden more than the debate about the Mohammad cartoons,” a source with knowledge of the matter told Expressen.

As Assange enters the final stages of his legal battle to avoid extradition to Sweden, his colleagues at WikiLeaks have begun preparing for how to prevent the Swedish government from extraditing the founder of the whistle-blower website to the United States.

“That the Swedish government doesn't take this seriously but rather makes it easier for the American government means Sweden finds itself among the countries that don't support transparency, the rights of the individual, and human rights,” the internal WikiLeaks memo reads.

“That puts Sweden and the country's reputation in great danger and the Swedish government is going to be forced to answer to global public opinion which will hold them responsible for not letting people around the world access information to which they have a right.”

WikiLeaks officials are convinced that Sweden has already made a deal with the United States that would see Assange extradited there to testify against Bradley Manning, the US soldier suspected of leaking thousands of classified US diplomatic cables to WikiLeaks.

There are also fears that Assange could be arrested and put on trial for espionage against the United States, WikiLeaks sources tell Expressen.

“If he's extradited, we fear for his life and that's something Sweden will pay a high price for,” a source said.

Among the documents WikiLeaks plans to make public is a US diplomatic report showing that Carl Bildt has served as an informant for the United States since the 1970s.

“There are secret documents that reveal that Bildt cooperated with the American administration in a way that violates Swedish law,” a WikiLeaks source told the paper.

“He'll be forced to resign. It will be the end of his political career.”

According to WikiLeaks, Bildt's original contact is political consultant Karl Rove, a former adviser to President George W. Bush, and someone who Bildt has openly referred to as “an old friend”.

While WikiLeaks spokesperson Kristinn Hrafnsson refused to comment on the details of the report about Bildt, she told Expressen “it's going to be released soon”.

Swedish foreign ministry spokesperson Anders Jörle said Bildt had nothing to say about the claims.

“We're going to hold off on commenting. We want to see what sort of document it is before we comment,” he told the paper.

However, Bildt acknowledged the Expressen report on his official Twitter account.

"Media reports that Wikileaks is planning what they describe as a 'smear campaign' against Sweden. Good to know," Bildt wrote, alongside a link to the Expressen article.

He also reacted to the report on his blog, challenging WikiLeaks "this in their opinion damning report".

"When that happens, this part of their planned 'smear campaign' will quickly fall apart," he wrote.