Germany has been one of the strongest supporters of the Euro, the Eurozone and the European Union. Throughout the EU sovereign debt crisis Germany banks were at the forefront of providing guarantees to ensure the financial systems in other EU countries did not collapse.

German industry relies on the weaker southern European economies to keep the value of the Euro low enough to make their exports competitive. And German Chancellor Angela Merkel has repeatedly affirmed German's leading role in the integrating European project.

Yet despite this unequivocal support, Southbank Research, a UK investment advisor believes the time may have come for Germany to pull the plug on the Euro, forcing other nations to leave the combined currency, risking the integrity of the EU itself.

Why would Germany have this change of heart? And what does this suggest about the fragility of the Euro, and the EU? Are the main EU nations committed to a policy of common interest; or are some members only part of the union because they cannot find an expedient way to leave?

Following the bailout of Greece by the International Monetary Fund (IMF), the EU and the European Central Bank, Germany was blamed for strict austerity measures in Greece. It was reported that Greece was a colony of Germany; and when in 2017 German banks received €2.9bn in interest on Greek loans, they were compelled to forego this in debt relief.

Less well reported is the perception of many Germans. And, according to the Southbank report, this could provide the impetus for Germany withdrawing its financial largesse.

Well before the Greek crisis, in 2004, the EU imposed fines on German banks - €3m in the case of Essen - for receiving subsidies from local states. These were deemed government guarantees, and illegal under EU law. Following the start of the debt crisis in 2009 many of these banks, deprived of their support, collapsed.

Then came the EU bailout of Greece - the brunt of which was borne by German banks and German taxpayers. The message from the EU was effectively: Germans are forbidden from supporting their own banks but must be compelled to support banks in other EU member states.

And while many attacked Germany for imposing financial discipline in a part of the Eurozone that failed to manage itself, the message was also sent that this bounty must be endless.

Greek politicians criticised the bailout, for merely restructuring the debt. The plan, they argued, bailed out German banks via Greece, giving little benefit to the Greek people.

Another claim often made is that Germany is one of the richest EU countries, and therefore has some obligation to provide for weaker members. In fact, this is untrue. By looking at median EU household wealth, Germany ranks below the EU average of €109.2k, at around €51k: lower than Luxembourg (€397k), Cyprus (€266k) and lower perversely than Greece (€101k).

European Central Bank policy has been to keep interest rates as low as possible, practically 0%. This has certainly benefited indebted southern nations; but has also sparked a huge mortgage boom in Germany as borrowing is cheap.

The negative effect on Germany is twofold. First Germans have seen how disasterously mortgage bubbles can burst in Ireland and Spain. Second the house price rises have not benefited most Germans as home ownership is low, and have merely inflated rents or made homes unaffordable to none but speculators.

And German banks bear the pain of Target2: the inter-EU bank system that stabilises the Euro across national economies. As German economist Thorsten Polleit notes "All these measures that have been implemented to drain German wealth to support ailing banks and prop up Europe... most people won’t realise because it’s so complex."

Italy has kept up the pressure on the Central Bank to provide ongoing support for the country. Last month Italy’s budget committee president Claudio Borghi stated: “either the ECB will provide a guarantee or the euro will be dismantled" as "there is no third option."

The final "stab in the back" is that when Germany joined the Euro Chancellor Helmut Kohl specifically confirmed such guarantees would never be made. "According to the treaty rules, the euro community shall not be liable for the commitments of its member states and there will be no additional financial transfers."

Former French finance minister and current IMF head Christine Lagarde explained these rules were ignored during the European sovereign debt crisis: “We violated all the rules because we wanted to close ranks and really rescue the eurozone.”

Germany has always been prepared to bear the pain of the bailouts because a return to the deutschmark would push the economy into recession, the currency being greatly overvalued compared with the euro, without the underperforming southern states.

But recently Germany has been considering capping Target2 balances. Wolfgang Steiger, the secretary-general of Germany’s governing political party’s economic council, told Bild.de about the plan: “We urgently need to limit or protect the escalating Target2 balances, which rose by as much as €54 billion to nearly €1 trillion in May alone.”

This is phrased as sensible financial management; but the fact is any such steps would unbalance the euro stabilising mechanism, making the currency unworkable. Mario Draghi dismissed the measures out of hand; understanding full well the proposal's implications.

Ironically in the USSR there was a similar rouble balancing mechanism to equalise the currency flows between the republics, which ended up placing unmanageable debt on the Russian Central Bank.

Politically neither Greece, Italy or Germany can be seen publicly to pull the plug on the euro. A behind the scenes manipulation on Target2 might just be opaque enough to obscure the blame game. But the longer everyone hangs on to this rising debt balloon, the greater the final fall is sure to be.