As any sensible person knows, insurance policies have value only when a) the purchaser has read and followed the small print; and b) the insurer is able to honour a policy sold to some unsuspecting punter long ago. Otherwise, a prolonged series of ultimately fruitless “But I thought I was covered …” arguments are likely to ensue. And so it is proving to be with the Hong Kong Chinese who acquired overseas citizenship – and the consular protection it seemed to confer – but who did not bother to renounce their Chinese nationality.

Singapore’s late prime minister, Lee Kuan Yew, never one to mince words – and to the chagrin of his critics, he was usually right – described the 1984 Sino-British Joint Declaration as simply giving the Hong Kong Chinese “thirteen years notice to leave”. And so it came to pass. In the years that followed, families departed in droves.

Back in the 1980s, Hong Kong Chinese “emigrants” to (mostly) Australia or Canada were spoken of locally – without irony – as having obtained an “insurance policy”. Their objective was to have a back-pocket escape hatch in case Hong Kong went to the dogs after the 1997 handover to China. The telling phrase implied that these people had little intention of participating in the national life of their new country, much less actually living there – or paying any more tax than they legally had to – for any significant length of time. With some exceptions, emigrants would stay just long enough to obtain an alternative residence before coming straight back home.

For Hongkongers, British National (Overseas) passport not worth the hassle

Various social phenomena – and the terms to describe them – emerged during this period. “Astronauts” were the principal breadwinners who remained in Hong Kong to keep the family business afloat and spent long periods inhabit­ing the flight paths to and from Sydney or Vancouver while their spouses and children sat out their time in “immigration jail” – another telling metaphor – in their intended country of citizenship.

Ingenuity was often deployed to gain alternative citizenship. In the early 90s, one acquaintance desperately wanted Australian residence status but did not qualify for entry. He was, however, eligible for skilled emigration to New Zealand. So this enterprising chap decamped to Auckland and, at the end of the required period, applied for citizenship. As he told it, “Eric” got his New Zealand passport on the Friday and left for Sydney – where he had wanted to go in the first place – the very same weekend. He never returned to New Zealand, but within 10 minutes of acquaintance, this proud Antipodean would carefully let everyone he met know – in a heavy Hong Kong accent – that he was “really” a Kiwi. He also kept his Home Return Permit current.

Hong Kong Chinese with two passports want best of both worlds

Back in the days when, internationally, China was a power that could be pushed around, this seemingly petty detail didn’t matter much. To be fair, some governments – Australia, in particular – made it clear before the handover that the desired consular protection for dual citizens born in Hong Kong would not be forthcoming after 1997 if they did not renounce their Chinese nationality. The more prescient did so, and consequently lost the “three stars” on their Hong Kong identity cards when they came to be renewed.

More Hongkongers renewing British overseas passports amid political unease

The majority, as ever, chose to have their cake and eat it. Or try to. Other popular “emigrant/investment visa” destinations remained publicly coy about this little technicality. And now, in the manner of all fibs and evasions, the truth is coming home to roost. To quote those age-old words of biblical wrath, “Be sure your sin will find you out …”