Huge prize means battle for Brexit banking jobs is getting down and dirty
Brexit will be bad news for the Irish economy - that's the near universal view and it's based on the reality that any future trading relationship between Ireland and the UK will be worse than the current, frictionless, regime.
Even the prospect of Brexit gains for the Irish financial services sector, and by extension Dublin, took its first big hit this week.
That was the stark warning from Financial Services Minister Eoghan Murphy that some rival locations may be actively undermining Ireland's effort to attract jobs that will leave the UK because of Brexit, by offering lower regulatory standards in exchange for the investment.
In unusually frank language he described "dangerous competition" for Brexit jobs and the potential for what he referred to as "regulatory arbitrage."
That's the market's polite way of describing the benefit of selling the same financial services from lighter regulated bases.
In theory it shouldn't be possible. Standards, and in many cases actual regulation, should be so similar across the European Union that no one location should be a softer base .
The reality is different. At an event in Dublin this week, Angela Knight, once a minister in John Major's government and now a financial sector grandee in the UK, explained: "The arbitrage is not so much the rules, as enforcement of the rules."
Now chair of investment firm Tilman Brewin Dolphin, she said that even when the same rules apply the consequences for getting caught breaking them are not always the same.
"The rigour of supervision, the size of fines" can all be different, she said. For EU regulations something as simple as translation into the national language can produce different results, she said.
On top of that, some cities are aggressively marketing themselves to banks and insurers in London in other ways.
The state government in Hesse, which includes Frankfurt, is talking about relaxing tough - read worker-friendly - labour laws to make it easier for free-booting banks to sack under-performing traders.
Paris, meanwhile, is letting global banks file French paperwork in English.
The potential prize is enormous. Insurers, banks and brokerages employ tens of thousands in London in some of the highest-paid jobs anywhere.
The City of London, Britain's beating financial heart, dominates the EU's wholesale banking, capital markets, insurance and specialist financing sectors.
Despite being outside the core Eurozone, firms in London are overwhelmingly the main players in the vast and lucrative business of turning European savings, pensions and insurance policies into the liquid currencies, shares, bonds and loans that fuel all EU economies.
British insurers, and global insurers using London, underwrite everything from consumer holiday cover to cross-border interbank lending.
The head of the Irish Stock Exchange, Deirdre Somers, rattled off the scale of what's involved at the same British-Irish Chamber of Commerce event where Angela Knight spoke.
Seventy eight percent of the European capital markets are in the UK, 76pc of passporting (selling financial services in other markets) is by UK firms, while 76pc of Europe's hedge funds are in Britain.
Swathes of that business are potentially up for grabs.
In Ireland the IDA is in the hunt for investment, but regulators are more wary of rolling out the red carpet.
The widespread view is that Irish regulators are playing it straight on Brexit - open to new institutions coming, but burned by our own crash, inflexible on standards such as the need to have substantial business here in order to be licensed.
In practice that approach may make it harder for a bank or insurer to shift here piecemeal from London because it can in effect be paying on the double for regulatory costs during the transition - which could easily last a decade.
It's still all to play for, but there are early indications are that Ireland may already be losing out. Since last June's vote to leave the European Union, around 150 jobs at Barclays Bank are Dublin's biggest Brexit dividend. Chinese banks with ties to the aviation leasing sector are growing in Dublin, though not so far in scale.
Last week Luxembourg scooped a major prize.
By contrast HSBC had announced plans to shift 1,000 jobs to Paris almost before the votes were cast. Goldman Sachs is widely reported in Germany to be shifting 1,000 of its top staff - including traders and executives -to Frankfurt.
Frankfurt, Paris and Dublin are tipped by many as the cities most likely to benefit from Brexit. But there's a real sense of flux. In Amsterdam, two of Japan's biggest banks, Mitsubishi UFJ and Mizuho, have been building their presence.
Milan and Madrid see themselves as viable European banking centres, and each is home to major financial institutions.
The specifics of the final Brexit deal will determine how many financial jobs leave the UK, but the battle to win them could become increasingly dirty in the meantime.