Greek PM Alexis Tsipras has announced a referendum on a controversial bailout deal with foreign creditors for July 5.
In a TV address, Alexis Tsipras described the plan as “humiliation” and condemned “unbearable” austerity measures demanded by creditors.
The Greek government earlier rejected the proposals, aimed at avoiding Greece defaulting on its debt.
Greece has to make a €1.5 billion ($1.7 billion) IMF debt repayment on June 30.
Alexis Tsipras said: “These proposals, which clearly violate the European rules and the basic rights to work, equality and dignity show that the purpose of some of the partners and institutions was not a viable agreement for all parties, but possibly the humiliation of an entire people.”
“The people must decide free of any blackmail,” he added.
Greece has refused to accept cuts to pension payments or public sector wages while the IMF is pushing for deeper spending cuts, not just more tax rises.
A key point of friction is a special benefit paid to some low-income pensioners, which creditors want scrapped.
Creditors also want a wider VAT base; Greece says it will not allow extra VAT on medicines or electricity bills, and has also resisted calls for VAT hikes on hotels and restaurants.
Athens wants a concrete commitment to debt relief, something its creditors are not offering.