BREXIT has been an “absolute pain in the backside” for Britain’s businesses but they have already factored in the worst case scenario - a no-deal - and are now looking beyond exit day.

The frank and sanguine view belongs to Peter Estlin, the 691st Lord Mayor of London, who, beyond the mayoral robes and gilded carriage that the office is publicly associated with, is in a more everyday sense the globetrotting ambassador for the UK’s financial and professional services sector.

This week, the elected head of the City of London Corporation, is in Scotland on a mission: to build up the relationship, both professional and cultural, between its political and business leaders and the Square Mile.

From his grand offices in Mansion House, a stone’s throw from the Bank of England, the apolitical Lord Mayor has watched the Brexit process unfold with as much concern as anyone else.

“The reality of Brexit, at the business level, has been an absolute pain in the backside,” Mr Estlin told The Herald.

“Brexit has been an administrative nightmare. Talking to a senior chairman of a bank, they have to physically move pieces of the jigsaw around. I know Barclays has moved 200 people, UBS 1,000.”

But the Lord Mayor explained there was, amid the Brexit gloom, optimism.

Read more: Scots hauliers fear no-deal Brexit will freeze them out of EU, Minister warns

“The world is not stopping for Brexit. Nor are we. Everybody else might be myopically focused on it, particularly down in Westminster, but we’re not.”

Yes, the City had lost 10,000 jobs because of Brexit but the “good news” was when the growth in fintech, green finance and cyber was taken into account, the City’s net gain in the last 18 months was around 25,000.

“The reality is businesses have prepared already,” stressed Mr Estlin. “One can crystal-ball gaze but the only thing certain today is you and I are both going to die and on March 29 we are leaving the EU with a no-deal. The only thing that will change that is if something happens. Parliament actually has to do something.”

Until it did, he explained businesses had to plan for the worst; “a no-deal; whether that’s on March 29, June 30 or some date in the future”.

And this planning, coupled with the changing work landscape of the digital revolution, meant companies had already moved beyond Brexit.

“What Brexit is not dealing with is the 21st century,” declared the Lord Mayor.

He explained the world had “already moved way beyond Brexit” to consider issues like the cross-border transfer of data and digital services, international taxation, intellectual property and contractual certainty.

Mr Estlin, who zips around the world from America to the Gulf and Singapore to Japan, talked of Britain as an “incubator nation” with huge levels of creativity and talent, high standards of regulation and large amounts of foreign investment.

One key part of the Lord Mayor’s role is ensuring sovereign wealth funds continue to invest in Britain and he pointed to how Norway’s, the world’s largest at £750 million, was planning to increase its investment in this country regardless of Brexit.

“If we go back through history, there is an attitude in our cultural aspect that we very seldom celebrate. If you go back through disaster after disaster after disaster, the phoenix rises.

“We had the Great Fire of London and, guess what, we created the greatest insurance market in the world,” he boasted.

Mr Estlin, who is taking a sabbatical from his role as a Barclays Bank senior advisor during his yearlong unpaid term of office, also sought to put Britain’s current obsession with Brexit into historical context.

“When the historians write the history of the 21st century, are they going to reflect that Brexit was an issue or, actually, the digitisation of industries and the move to the fourth industrial revolution was the major thread of the 21st century? I think it will be the latter.”

In the next three days, the 58-year-old urbane businessman will be in Glasgow and Edinburgh, talking to the likes of Aberdeen Standard Life, the Law Society of Scotland and Scottish Financial Enterprise as well as Derek Mackay, the Scottish Government’s Finance Secretary.

He will be encouraging captains of industry to accompany him on foreign trips to access growing markets and to set up offices in London to “tap into” the potential of the financial magnet that is the City.

“So, 34 per cent of capital raised is here, 30 per cent of international bonds are raised here, over 250 banks are here, and in terms of professional services’ access, how do we help connect Scottish businesses to this international platform?”

The Lord Mayor spoke also of enhancing the City-Scotland relationship, covering not just business aspects but cultural ones too such as promoting the Edinburgh Festival.

In January, the Mansion House hosted a Burns Night Supper, at which Nicola Sturgeon, the First Minister, spoke.

"Believe it or not, it was[the first time]. And it’s something we’re going to repeat,” said Mr Estlin.

He pointed out how Edinburgh was a major management asset hub and Glasgow had a growing fintech centre, so that, just as with Brexit, were Scottish independence to happen, it would not faze the City of London.

“In a scenario where Scotland were an independent country, then the reality is it still has great asset management businesses. Well, we have got a great amount of capital sitting here in London. How do we connect the dots?”

The Lord Mayor pointed out with pride how he was the only dedicated finance sector ambassador anywhere in the world.

“We have been doing this role for 830 years. I’m not saying we’ve always done it perfectly but why is Tokyo now thinking for the first time in its history about having a financial mayor? Maybe we have been doing something right for 830 years.”