IT has surely not been a good week for all those Brexit supporters who believe, in spite of the colossal weight of expert opinions and evidence to the contrary, that leaving the European Union will somehow be good for the UK economy.

The flurry of downgrades of forecasts for the UK economic outlook has intensified, with the International Monetary Fund (IMF) and accountancy firm PricewaterhouseCoopers (PwC) this week warning of a sharp slowdown in growth, as the consequences of the Brexit vote manifest themselves.

Wolfhart Hauser, chairman of Aberdeen-based FirstGroup, has meanwhile flagged the danger that the vote by the UK electorate on June 23 to leave the European Union could dampen growth in the company’s bus and rail businesses.

And a survey from the Royal Institution of Chartered Surveyors has highlighted the already detrimental impact of the Brexit vote on the Scottish commercial property market. In the UK as a whole, commercial property has been among the high-profile early casualties of the absolute shambles and great uncertainty that has arisen from the decision to leave the EU.

There seems to be a solid consensus among the vast bulk of economic soothsayers that the impact of Brexit will be significantly negative. This degree of consensus among economists tends to be unusual. Probably the last time the economic forecasters were in such miserable harmony was back in 2008, when it became clear that the global financial crisis was going to usher in recession and there was nothing anyone could do about it.

John McLaren, honorary professor at the University of Glasgow’s Adam Smith Business School, this week warned Scottish economic growth prospects are bleaker now than at any time since the financial sector-induced crisis of 2008. His comments came after figures from the Scottish Government revealed the economy north of the Border stagnated in the first quarter.

It is difficult to disagree with his analysis. And, although Mr McLaren cites the uncertainty north of the Border arising from the prospect of a second Scottish independence referendum, we would probably also have to look back to 2008 to find when the prospects for the UK economy as a whole were last this grim.

Things were not looking great even before June 23, with the UK economy having been held back for years by a seriously overdone Conservative austerity programme that has also featured entirely the wrong mix of measures. However, the Brexit vote has certainly put the tin lid on things.

The IMF prefers the description of the Brexit result having “thrown a spanner in the works”, which is just as apposite and perhaps more so given the likely negative impact of the Leave vote on UK manufacturing. There have already been plenty of rumblings about negative consequences from global car manufacturers, but grave uncertainty over continued access to the single market will have ramifications throughout the industrial sector in Scotland and elsewhere in the UK.

The short attention spans of financial markets were thrown into stark relief again this week when sterling rose on the back of a report from Bank of England agents that there was no clear evidence yet of a sharp general slowing in activity following the Brexit vote.

This is surely no kind of comfort at all. If you look at the experts’ forecasts, the economic damage is expected to be seen more clearly in 2017 than this year, after the grisly business of the Brexit negotiations with our long-suffering EU partners gets under way in earnest. That said, there are already plenty of harbingers of the economic woes to come for those who want to see them.

What is more, the Bank of England agents noted a marked rise in business uncertainty and observed companies formulating new strategies in the wake of the Brexit vote. And the agents found that about one-third of their contacts throughout the UK believed the vote to leave the EU would affect their staff hiring and investment plans negatively over the next 12 months. Surely this does not bode well for the future. That is a big proportion, and a lot of investment and hiring decisions.

Jeremy Peat, visiting professor at Strathclyde University’s International Public Policy Institute, this week flagged an inevitability, whatever happened with Scotland’s efforts to stay in the EU in line with the wishes of its electorate, that the Brexit vote would dampen corporate investment over the next 12 to 24 months. He fears domestic companies and potential inward investors will hold or scrap projects.

Another point on which most economists agree is we are in uncharted territory and face huge uncertainty.

PwC warned the risks were weighted to the downside, and flagged the possibility the UK economy could contract by one per cent next year, rather than grow at the weak 0.6 per cent rate projected in its central forecast. It sees the downside risks crystallising if there is a lack of early progress by the UK in its efforts to retain access to the single market.

The IMF has cut its UK growth projection for 2017 from 2.2 per cent to 1.3 per cent and reduced its forecast of expansion for this year from 1.9 per cent to 1.7 per cent, but appears to be among the more optimistic of forecasters.

Fund management giant BlackRock forecasts the UK will now enter recession in the coming year, following the Brexit vote. And economists polled by Reuters in the last week or so put the median probability of UK recession in the coming year at 60 per cent.

As the grim forecasts rain down, some Brexiters might want to join the rest of us in recognising the reality of the situation. Unfortunately, that will not change the economic weather.

Meanwhile, we read about some Brexit voters’ desire to ensure the Crown stamp is put on pint glasses. It all feels like a bad dream. Sadly, it is not.