‘In or out?’ is not just a question for the Scots in two months’ time in relation to the UK; it’s also a question for the UK right now in relation to Europe.

And despite usually being such a Conservative bunch, the central London property industry would far rather we remain in.

The City and Westminster Property Associations, which represent more than 400 major central London property owners, developers and investors, issued a ‘Manifesto for Growth’ this week, warning that uncertainty over the UK’s relationship with Europe risks damaging the UK’s international competitiveness and driving trade and investment elsewhere.

If the UK exits, international businesses will have one less reason to stay in London, it argues.

You only have to talk to Canary Wharf Group boss and “enlightened builder” Sir George Iacobescu - as Property Week does on page 30 - to get an idea of what impact that could have on the London property market.

At the moment, the group is attracting interest from a growing array of international investors, its sale of a 70% stake in 10 Upper Bank Street last month to the world’s biggest insurance company, China Life, case in point. Not only was it the biggest deal done to date by a Chinese company in London, it was also the insurer’s first major acquisition in the UK. As Sir George says, London is regarded as a “safe place and the place they expect to do business”.

The question is: would that appetite wane if the UK exited the EU? Then there’s the resi market to consider. Again, it’s attracting a huge amount of foreign investment - some would argue too much given the prospect of a housing bubble, although not Sir George. “Foreign money stimulates the economy.

The Chinese want to invest, the Malaysians want to invest. You can complain about foreigners buying, but you should look at yourself in the mirror and say: aren’t we a great city and country where everybody in the world wants to come?”

Would that appetite wane if the UK exited the EU? Daniel Van Gelder, chairman of the Westminster Property Association and co-founder of Exemplar, fears it might. “It’s all about certainty,” he says.

“The big problem is the thought of a referendum creating uncertainty in the market.”

As the Scots appreciate all too well. Only last week, we reported how badly the Scottish property market has been affected by the uncertainty created by its impending referendum. The last thing the London property market needs is for the same thing to happen in the capital.

After all, it’s not just the London market that’s at stake at what is a critical juncture in the recovery, with the regions stillfragile and even the capital vulnerable if the pound continues to strengthen.

When it comes to the UK and Europe, what concerns the industry is the negativity of the campaigning, which is why Van Gelder and co are so proactively lobbying for more political recognition of the industry’s importance ahead of next May’s general election.

So how real is the threat? Judging by new foreign secretary Philip Hammond’s reiterated warning this week that if the EU fails to agree to new terms for UK membership, he’d rather leave the bloc, pretty real.

Whether that’ll be enough to change the property industry’s traditional political colours from blue to red, now that’s a different question altogether.