"This step would save Greece's budget billions of euros, while reforming the Troika arrangement, eliminating the IMF's and the ECB's financial exposure to Greece," said Jacob Funk Kirkegaard, senior fellow at the Peterson Institute for International Economics, who advocates such an arrangement.
It would lower the effective interest rate on Greek debt to less than 2 percent, far less than Athens was paying before the euro zone debt crisis began in 2009, and radically reduce the principal amount to be repaid over the next decade, giving Greece fiscal breathing space to revive its economy.
Read MoreGreece: The next deadline approaches
And unlike ideas floated by Greek Finance Minister Yanis Varoufakis to swap euro zoneloans for GDP-linked bonds and ECB holdings with perpetual bonds, paying out the IMF and the ECB early would be legal and supported by precedent.
But if the economics make sense for Greece, the politics no longer add up for its partners.
A euro zone official said there had been exploratory talks with the previous conservative-led Greek government about such a plan last year, before then Prime Minister Antonis Samaras chose to bring forward an election he lost rather than complete a bitterly unpopular bailout program.
"Now it's a political non-starter," said a euro zone official. "There's just no appetite in theeuro zone for a grand bargain to take over Greece's debt to the IMF and the ECB."
Tsipras' denunciations of EU-prescribed austerity, demands for German war reparations and cozying up to Russian President Vladimir Putin, and Varoufakis' foot-dragging on reform negotiations and initial calls for a "haircut" on Greek debt, have dried up the reservoir of sympathy for Athens.
Creditors like Germany, the Netherlands and Finland are bent on keeping the IMF involved as an enforcer of economic reform and fiscal discipline because they don't trust the Greeks to keep their word, nor the European Commission to hold them to it.
"They would prefer to provide debt relief on an annual basis so they keep leverage onGreece to stick to the program," said Miranda Xafa, senior scholar at the Centre for International Governance Innovation and a consultant on Greek debt.
True, euro zone peers Ireland and Portugal, which received international bailouts after Greece, won EU agreement to pay off their costlier IMF loans faster, raising hopes in Athens.