The mayor was fundraising for his preferred plan before tender even went out, giving unfair advantage to his favourite designer. London assembly member Tom Copley says the project must be stopped now

Heatherwick Studio's Garden Bridge design

If I asked three companies to compete to design a car for me, but privately told one of them that I wanted it to be a red convertible, would it surprise you if that company happened to produce the winning design? This is exactly what has happened in the case of London's Garden Bridge design contract.

There has been little doubt in the minds of those of us who have been following the saga of Joanna Lumley’s brainchild that Heatherwick Studio had been given an unfair advantage in the design competition. Just before the tender was put out for what was then rather uninspiringly called the “Temple to South Bank footbridge” Boris Johnson flew to San Francisco for a 24-hour £10,000 taxpayer-funded trip to drum up private sponsorship for it. He subsequently refused to say whether anyone from or associated with Heatherwick Studios had been with him on the trip. Now, thanks to an exposé by the Architects Journal, we know that Thomas Heatherwick was there.

Boris Johnson travelled to the United States to raise money for a garden bridge before a tender had been put out

Why does this matter? Well, isn’t it odd that the Mayor of London, who is also Chair of Transport for London, should he promoting a design for a project that hadn’t been put out to tender yet? When the contract was tendered, TfL ignored its own legal advice by opting to select three bidders. They split the design contract from the engineering contract to avoid having to go through the usual OJEU open tendering process.

The brief given to the three bidders: Marks Barfield, Wilkinson Eyre and – of course- Heatherwick Studios, was for a pedestrian footbridge. Nowhere did the brief mention that what was really desired was a Garden Bridge. Marks Barfield and Wilkinson Eyre duly produced designs for a pedestrian footbridge. Meanwhile Heatherwick Studios – lo and behold – came up with just what the Mayor wanted: a Garden Bridge.

The tendering process attracted such concern that TfL conducted an internal audit of it at the request of then Transport Commissioner, Peter Hendy. The resulting report was widely condemned as a whitewash, and a far more critical earlier draft was leaked. Yet still both the Mayor and TfL denied any wrongdoing.

At our GLA Oversight Committee I challenged TfL’s Richard di Cani, now TfL’s Managing Director of Planning, who assessed the three bids, as to how it could possibly be fair that one bidder was party to information that the others were not. He refused to acknowledge there was any unfairness, simply asserting that Heatherwick had produced the best design.

When assessing bids such as these, TfL uses a scoring system. Let’s remember that Heatherwick Studio had only ever designed one bridge. Marks Barfield and Wilkinson Eyre between them had designed 25 bridges. Yet in the category which scores “relevant experience” (i.e. experience of designing bridges) Heatherwick scored just marginally below the other two companies.

It’s worth reminding ourselves too that Heatherwick Studio seem to be a favourite of the current Mayor. Hetherwick was commissioned to design the mobile sauna known as the New Bus for London (Boris Bus, or “roastmaster”).

The "Roastmaster" bus designed by Heatherwick Studio

Perhaps one of these issues in isolation could be excused. But there is a clear pattern of proper procedure not being followed, and actions taken that to any neutral observer appear to advantage Heatherwick Studio. There’s no doubt that the Heatherwick design was strongly favoured by Joanna Lumley – herself an associate of Heatherwick Studio – and as I’m sure Phil Woolas would testify, no politician wants to get on the wrong side of her. Her passion for the project may be admirable. But where public money is concerned the Mayor of London cannot be – or even be perceived to be – unduly influenced to favour one designer over another.

The Heatherwick design was strongly favoured by Joanna Lumley – herself an associate of Heatherwick Studio

But the most significant piece of evidence pointing to a rigged process is Boris Johnson’s own shiftiness when questioned about it. He was asked in December to provide a list of those who were with him on his San Francisco trip and agreed to subject to “advice”. A month later when I questioned him about it at Mayor’s Question Time, he still hadn’t produced a list, but again agreed to do so subject to advice. He refused to say, when asked directly, whether anyone from Heatherwick was with him. In the end the evidence was discovered buried in an FOI.

If I were one of the two companies who lost out in this rigged procurement process having spent time and money on bids, I’d be livid. Given what we now know, I don’t see how it’s possible for the Garden Bridge to be built.