Julian Assange has declared that WikiLeaks, the whistleblowing site he founded, must suspend its publishing operations to raise funds to prevent bankruptcy by the end of 2011.

The site has been fighting what it calls a “financial blockade” after payment companies and banks, including Visa, MasterCard, PayPal and Bank of America, stopped processing donations to WikiLeaks in December last year. Mr Assange said this now posed an “existential threat” to WikiLeaks’ work, saying it had deprived the organisation of tens of millions of euros in funding.

“In order to ensure our future survival, WikiLeaks is now forced to temporarily suspend all publishing operations in order to direct all our resources into fighting the blockade and raising funds,” Mr Assange told a press conference at the Frontline Club, a private members’ club for journalists in London. “If Wiki-Leaks does not find a way to remove this blockade, given our current levels of expenditure, we will simply not be able to continue by the turn of the year.”