The ESM and the earlier European Financial Stability Facility have paid out €246.1 billion to Ireland, Portugal, Spain, Cyprus and Greece combined since 2010, cleaning up sovereign balance sheets by offering low-interest bonds, in the process saving the five countries more than €20 billion in 2013 and 2014, according to ESM data.

Solely euro denominated and paying a coupon between 0 per cent and 3.875 per cent depending upon maturity, around 20 per cent of the ESM bonds have been sold to Asian investors, including central banks, insurance companies, hedge funds and pension funds.

(Regling would not say if the Hong Kong Monetary Authority Reserve Fund was an investor and the HKMA does not give a breakdown on its holdings.)

Additional currency options may make it easier to market ESM bonds but they will not get the green light if borrowing costs exceed the euro bond equivalent, Regling said.

“What he will have to wait for is for China’s (interest) rates to match Europe,” for a yuan bond to work, said Michael Every, head of financial markets research at Rabobank. Even then, ESM bonds should ideally stay in euros, Every argued, as “why let foreigners dictate terms.”

A career civil servant once tipped to be European Central Bank governor, Regling is cooly clinical in his support for the widely unpopular programme of debt restructuring and austerity that has triggered riots and helped bring down governments.

“The moment a country loses market access and needs a special adjustment programme in order to qualify for financial support...something went wrong in that country...And the idea behind conditionality is that exactly the reasons that led to the problems need to be tackled.”

“The bottom line is: structural reforms must continue. It is a permanent challenge for every country, even for those who do well at the moment.”

Euro zone current account balances and labour costs are all moving in right direction, he said, while growth rates, when adjusted for demographics, are the same as the US.