THE departure of Greece from the euro has gone from impossible, to plausible and now almost inevitable—almost regardless of the outcome of this weekend's Greek election. Indeed, some well-placed figures are starting to whisper that Greece leaving the euro may be a good thing after all.

Long before the notion of "Grexit" became commonplace, some economists such as Nouriel Roubini argued that Greece's only chance of salvation would be to return to the drachma and devalue the national currency in order to regain competitiveness. Structural reforms and internal devaluation of the kind currently being attempted would take too long, and cause a social backlash. Departure from the euro would be less horrendous than staying in, Mr Roubini said on the margins of an Ambrosetti workshop in Cernobbio, on the shore of Italy's Lake Como, last March. But it would be painful enough to discourage others from attempting it.

Intriguingly, some prominent voices in Brussels and elsewhere are starting to weigh other benefits of Grexit. This is not because they think it can be done painlessly. Even if first-order contagion through the banks can be contained with the various euro-zone rescue funds (and the European Central Bank), many think that breaking the integrity of the euro will immediately raise questions about the future of other countries in the single currency: Ireland, Portugal, Spain or Italy.

Yet it is precisely this fear of meltdown that the pro-Grexit voices regard as beneficial. Why so? Because the danger of implosion will force Germany finally to agree stand unambiguously behind the euro.

This could be done through “banking union” in which responsibility for supervising, winding down and recapitalising big banks is done by some supranational European system. Another option is “fiscal union”, in which at least some of the sovereign debt is mutualised through jointly issued Eurobonds. Doing both would even more convincingly break the deathly embrace of zombie banks and zombie sovereigns.

A second argument is this: if Grexit provides the powerful impulse for integration, it would also remove the greatest impediment to it. It is hard to imagine any country, let alone Germany, being willing to assume liability for Greek banks that may be about to implode, and for the national debt of a state that has failed to abide by Germany's prescription for reforms (Reuters had an insider's view on Germany's exasperation with Greece here).

German officials have a tendency to go out of their way to praise other troubled countries that are reforming, if only to highlight the failures of Greece, and to express their bemusement at the markets' inability to understand the good that is being done. If Hellas is gone, the pro-Grexit argument goes, then Germany would have fewer excuses to refuse to deploy its full economic might behind the rest of the euro zone.

Such musings have been doing the rounds for some weeks. It was surprising, though, that the British chancellor of the exchequer, George Osborne, saw fit earlier this week to publicise such thinking.

I ultimately don't know whether Greece needs to leave the euro in order for the eurozone to do the things necessary to make their currency survive. I just don't know whether the German government requires Greek exit to explain to their public why they need to do certain things like a banking union, eurobonds and things in common with that. I would suspect that if you had a eurozone finance minister here, they wouldn't really know the answer to that.

So is Germany thinking of Grexit? I have spent most of the past week in Berlin with fellow journalists from Brussels, and nobody we have met was ready to entertain such a prospect, even in “deep background” conversations. The line is that Germany wants to see Greece stay in the euro – as long as it complies with the terms of its austerity and reform programme. The decision to stay or go will be for the Greek people to take. If Greek politiciains think they can scare the euro zone into renegotiating the bailout deal, they will get short shrift. No government will be able to justify lending billions more to a country that does not even make a semblance of playing by the rules.

One has to assume that, so some extent, German officials want to send a tough signal to Greek voters. And if one listens carefully to the discourse in Berlin, there seems to be a bit of room for negotiation - even if Alexis Tsipras, leader of the radical anti-austerity Syriza, should become prime minister.

If the next Greek government wants to re-arrange the budget to spend more in some areas and make savings elsewhere, that could be discussed, say officials. If it abides by the bailout terms, then perhaps it could get more help in the form of technical assistance. Or perhaps it can be given more time to meet its fiscal targets if recession is deeper than forecast (it usually has been). Indeed, some are even dropping hints of “targeted transfers” from rich to poorer countries of the euro zone. Whether any of this will be enough for Mr Tsipras, or indeed other Greek leaders, is another matter.

Angela Merkel, the German chancellor, is said to be of two minds about the departure of Greece. “She is a clever woman who is not an economist, surrounded by economists giving her contradictory advice,” says one close observer. Cautious by nature, Mrs Merkel is playing down suggestions that she is preparing a big leap towards integration. Then again, she probably does not want to risk the turmoil of ejecting Greece from the euro if she can possibly avoid it.

So any margins of manoeuvre are tight. For Germany, the idea that agreed rules of economic behaviour should be flouted is even more corrosive to the future of the single currency as the idea that a country could leave the once-irrevocable single currency. Instead of greater mutual liability, Germany is now pushing for more mutual rules (see my column is here). If these cannot hold, then better to let Greece go.

That may provide a third rationale for Grexit: to serve as an example to recalcitrant reformers. Some in Berlin have shifted from thinking about how to help Greece stay on board to how to manage its departure (central banks are preparing too). In particular, there is concern about avoiding a humanitarian catastrophe – if only to keep the lights running in hospitals - should official bailout loans be halted.

But what if Antonis Samaras, leader of the mainstream pro-bailout New Democracy party, manages to squeak ahead? This may only delay the reckoning for Greece. Even before the next formal report by EU, ECB and IMF officials is written, the Greek reform programme is known to be far off track, not least because its economy has been in suspended animation during the political upheaval of the elections. In the best of circumstances, Greece will require still more billions worth of loans that nobody wants to provide.

So if and when it takes place, Grexit may happen more by default, because all sides have exhausted their political capital, than by design.