This is the standard argument, but I don't think it's a very strong one.

You can't pick up and move a steel press, but you can build a new one in a new country. Assuming it's a welcome development, that is mostly just a matter of investment money and building time. Hiring local staff to run it is probably relatively straightforward.

Financial services, as you point out yourself, are all about the people. It's an industry built on experience and knowledge. Obviously today many of those people work in the City and live within range of the City. There is also an ecosystem built around the City to support that work.

As far as I can see, nowhere else within the EU currently has anywhere close to that level of capability and established supporting infrastructure. There are only two ways that is going to change: either large numbers of existing staff from the City or maybe other global financial hubs are convinced to relocate to other member states where the new facilities are being set up, or a new generation of staff is developed locally.

Clearly either of those is possible, as is some sort of hybrid. However, I find the most common argument -- that large numbers of City workers will just transplant their entire lives to a whole different country to keep a job -- unlikely. People talk about emigration to the EU a lot since Brexit became an issue, but the reality is that few people have actually done it while we're an EU member state and it is relatively easy, and it could become a much more significant and permanent change after Brexit. That leaves the alternative of building up a local workforce in some new location, but that also means building a new financial centre to challenge the City. At best that is going to take many years, during which presumably access to big finance across the EU27 would be significantly worse than today, and even then it would be a risky endeavour that might never provide the alternative that people were hoping for.

As I said elsewhere, I hope cooler heads will prevail. The alternative to this is that the EU and UK negotiators grow up and realise that continuing relations in this area is hugely in both parties' best interest. If some deal is reached on financial services then the UK financial sector doesn't take a significant hit, and EU27 businesses and governments can continue to rely on the financial services they need with relatively little change or risk. It's hard to see how any plausible alternative isn't much worse than this in the short and probably medium term.

A chunk of them already have moved country: https://news.efinancialcareers.com/uk-en/231364/percentage-o...

Not a majority, no, but it's inherently a very international business and the more money is at stake the more willing people will be to move.

It matters a great deal what the UK immigration regime will be after Brexit. The government has refused to give any clarity on this, and there are warning signs that the Home Office would very much like to start treating EU nationals as illegal immigrants. If no agreement is reached otherwise, it will be illegal for all those EU nationals to be employed, rent a house, or have a bank account.

I'm not saying it will be an overnight collapse, but more likely a slow melting away of new business and gradual movement of e.g. Euroclearing. In the short term it may be as simple as moving the flag which says where the company's HQ is and moving its taxpaying nexus inside the EU.

You're also underestimating the willingness of those financial businesses which are within the EU to be comfortable with UK competition.

Agreed, and this is an area where the facts seem quite clear and I'm hoping that sanity will prevail by the time the dust settles. In fact, what I'm really hoping is that the whole Brexit mess will force the government to fix our immigration and visa system more generally. It's already insanely slow, complicated and unpredictable for those legitimately visiting or moving here more permanently from outside the EU, and that doesn't really help anyone.

For what it's worth, I have no idea where your characterisation of the desired future treatment of EU nationals as illegal immigrants come from, and I think your predictions here are unlikely to the point of being almost inconceivable. The government might have to pay lip service to immigration controls up to a point, but they've been doing that for years anyway. I can't believe even the current lot are foolish enough to undermine the NHS, the education system, the tech and creative sectors, and so on with the kind of draconian system you seem to be envisaging.

I'm not saying it will be an overnight collapse, but more likely a slow melting away of new business and gradual movement of e.g. Euroclearing.

Perhaps. That's certainly a possible outcome in the longer term. Presumably whatever happens in terms of Brexit, any transition, and then any final deal beyond that, the economies on both sides of the Channel are going to adapt in time.

In the short term it may be as simple as moving the flag which says where the company's HQ is and moving its taxpaying nexus inside the EU.

This I find less likely. Various EU governments, notably including the Germans (albeit under the previous administration), have made it very clear that they don't want to see that sort of "technical" movement. And it's going to be very hard for the financial services firms to play games if the national regulators in their new home state(s) want to cause problems for them.

*You're also underestimating the willingness of those financial businesses which are within the EU to be comfortable with UK competition.

Given the scale we're talking about here, I'm curious to know which financial businesses you classify as being "within the EU" at present.