ATHENS — Finance Minister Yanis Varoufakis of Greece said on Thursday that he would resign immediately if Greeks voting in a referendum on Sunday endorse efforts to secure an international bailout deal for the country. His comment is the starkest sign yet that the government of Prime Minister Alexis Tsipras is likely to be reshuffled or could even fall if a yes vote prevails.
Mr. Tsipras’s government has been exhorting Greeks this week to vote no in the referendum, which, while couched in confusing language,
effectively asks whether the nation is willing to accept more austerity in exchange for billions of euros that the country needs to return to solvency.
After a remarkable series of twists and turns in negotiations with creditors this week, the proposal on which Greeks will be voting is no longer even on the table, as the bailout package expired Tuesday night.
Nonetheless, in televised remarks and interviews played on repeat on almost every Greek television station, Mr. Tspiras and Mr. Varoufakis have urged Greeks to vote against the package. They say that a no vote would give the government a stronger hand in negotiations with Greece’s creditors to repudiate austerity and to compel them to give in on the country’s biggest demands: reducing its mountainous debt load, one of the world’s largest.

If Greeks instead vote yes, it would signal their desire to accept the bailout with austerity conditions that Mr. Tsipras has been pushing against, and it would effectively be a repudiation of Mr. Tsipras and his government’s negotiating strategy. That could lead not only to Mr. Varoufakis’s resignation but also to the withdrawal of numerous other government members from Mr. Tsipras’s leftist Syriza party — and possibly of Mr. Tsipras himself.

In an interview with Bloomberg Television on Thursday, Mr. Varoufakis said that he would not remain finance minister after a yes vote, but that he would help his successor steer Greece out of its debt crisis. He added that he would “rather cut off” his arm than sign a new deal with creditors that does not restructure Greece’s debt.

In many ways, Mr. Tsipras’s negotiating tactics have always been about achieving his government’s overarching goal of reducing Greece’s debt burden, which Mr. Varoufakis has argued time and again is unsustainable.
By continuing to accept bailouts with austerity conditions, Mr. Varoufakis argued in an interview after being installed as finance minister in January, Greece has piled debt on top of debt, while subjecting its people to “fiscal waterboarding, where we are constantly having our head held under water.”

In a blog post Wednesday afternoon, Mr. Varoufakis offered six reasons Greeks should vote no in Sunday’s referendum.
But an opinion poll on Wednesday by euro2day.gr showed that the results of the referendum were too close to call, with 47 percent planning to vote yes and 43 percent veering toward the no position that Mr. Tsipras’s government wants.