Ben Chu: Towering headache

Outlook A massive slump in construction is part of the reason our economy has been stagnant.

One grand project approved just before the 2008 crash was Gerald Ronson's Heron Tower. The 46-story building in the City was completed in 2011 but has struggled to attract corporate tenants.

Despite boasting Europe's largest aquarium in its foyer, the Heron is just 60 per cent full. Now the project's £300m debt pile is, apparently, due to be refinanced.

That's potentially bad news for the equity investors who, given the likely slump in the project's value, could be called on to inject more cash. It's not just the Heron Tower's fish that are underwater.

Not that Mr Ronson himself needs to worry too much. Most of the equity is thought to have come from Middle East. A salutary lesson, perhaps, for those wealthy foreigners who seem to think that the London property market is a one-way bet.