Hong Kong and London are both global financial centres wracked by political chaos. The idea that this surprise bid comes at a suitable time for the 448-year-old London Stock Exchange to give up its hard-earned independence is preposterous.
Together with the Bank of England and the insurance market Lloyd's of London, the Stock Exchange is one of the three pillars of the City, with foundations dating back to the 16th century.
Of course, this is just the latest in a series of unsolicited bids. Since the turn of the millennium, the LSE has been bombarded with takeover offers from Sweden, Germany and New York. But it has refused to surrender. Indeed, each time, it has come back stronger and proved one of the best performing shares in the FTSE 100.
The Hong Kong Stock Exchange put in a £30 billion bid on Wednesday to buy the London Stock Exchange
The idea of this cornerstone of British finance falling into the hands of unstable Hong Kong - and potentially to Chinese control - should be unthinkable.
Even though it's paralysed trying to solve Brexit, the Government and regulators should be straining every sinew to stop the deal.
Post-Brexit, the London market must be the platform for the country's re-energisation. It is among the largest, busiest and most important in the world - attracting major natural resources companies from Australia, Canada, Brazil and Russia and South Africa. It is the envy of other European exchanges and owns the Borsa Italia, which is the dominant trader in bonds issued by European governments.
If our enfeebled Government lamely allows Hong Kong to get its wish, or steps aside and adopts a hands-off approach in a bidding war, it would be a gross betrayal of the country's ambitions to maintain its global leadership in finance after Brexit.
The timing of the Hong Kong Stock Exchange offer could not be more awkward. And not just in terms of Brexit
The timing of the Hong Kong Stock Exchange offer could not be more awkward. And not just in terms of Brexit.
Hong Kong is suffering violent pro-democracy demonstrations against its Beijing masters. This social disorder has shaken the big, British-origin mercantile groups, the Hongs, which still have a strong hold on the territory's commerce - from banking to airlines.
Nevertheless, the Hong Kong exchange audaciously saw the opportunity to swoop on the LSE following a successful bid for the much smaller London Metal Exchange in 2012 which was waved through by regulators.
The Hong Kong exchange audaciously saw the opportunity to swoop on the LSE following a successful bid for the much smaller London Metal Exchange in 2012
It may be counting on the Johnson Government welcoming the deal as a gesture of faith in post-Brexit UK. But it is also cynically exploiting the fact that Britain has become a bargain basement for foreign buyers as the pound has slumped and London shares have under-performed their counterparts on global markets.
The brutal truth is that an independent LSE is a key element of the City of London's enormous success. The Square Mile generates a trade surplus of at least £60 billion a year, making it the most successful sector of the UK economy.
It is hard to believe that such a bold move could have been attempted without the support of the Chinese government
Most worrying is the fact that although the Hong Kong exchange is independent, it is hard to believe that such a bold move could have been attempted without the support of the Chinese government. It is no wonder MPs have warned ministers of the foolishness of allowing the Hong Kong bid to proceed.
That said, this is a very delicate issue politically. The UK has most unwisely become dependent on Chinese finance for big infrastructure projects, and ministers must be careful not to alienate the Beijing government.
But the Johnson Government should not be panicked into thinking any good can come from allowing a major buttress of the UK's prosperity to be sacrificed.