Labour has written to Boris Johnson asking him to account for his role in the scrapped £46m London garden bridge project, after the foreign secretary had said he could not recall the reasons for key decisions he made.

The letter, from the shadow communities secretary, Andrew Gwynne, challenges Johnson over his claim earlier this month that a prominent journalist who has criticised the project was motivated by a personal dislike of its designer.



Gwynne demanded Johnson provide evidence for his allegation against Will Hurst, the managing editor of Architects’ Journal who has won several awards for his coverage of the garden bridge, or withdraw them and apologise.

The letter adds to the pressure on Johnson over his role in the troubled story of the planned pedestrian link across the river Thames, which he commissioned and championed as mayor of London, a job he held until May 2016.

In total, £46.4m of public money was spent on the project, but construction never began. The public liabilities, initially capped at £16m, escalated in 2016 when funding for a construction contract was released even though it appeared the stipulated conditions were not in place for this to happen.

Facebook Twitter Pinterest Artist’s impression of the proposed garden bridge across the river Thames. Photograph: Heatherwick Studio/PA

Appearing before the London assembly’s oversight committee earlier this month, Johnson insisted the funding conditions had been met by the charity behind the project, the Garden Bridge Trust, but he was questioned as to why he had made a mayoral direction in April 2016 that watered down some of these conditions.



Johnson said the explanation was “something which, I’m afraid, I simply don’t have, at this distance in time”.

At the same session, Johnson launched a vehement attack on Hurst, who won a British journalism award in December for a series of stories uncovering problems with the project.



The stories, Johnson said, were “motivated to the best of my knowledge by a dislike that the Architects’ Journal journalist concerned had for Thomas Heatherwick, who is not conceived of as being a proper architect, and is therefore somehow worthy of abuse”.

Hurst has vehemently denied this, pointing out that Architects’ Journal gave Heatherwick an award in 2015 for his contribution to the profession.

Gwynne’s letter says Johnson should answer questions on “the role played by your office in the reckless decision to release public funds for the construction contract”, including what role he played in releasing the construction funding.

It queries Johnson’s claim before the London assembly that the garden bridge project had “secured every relevant planning permission”, saying this was not the case.

The letter ends: “Do you have any evidence to support your public claim that articles published by Mr Hurst are motivated by a dislike of Thomas Heatherwick, if not, do you want to withdraw this comment and apologise?”

Johnson has repeatedly denied any wrongdoing over the scheme, insisting it would have been a success had it not been cancelled by his successor, Sadiq Khan, who was concerned at rising costs and a lack of funds raised by the Garden Bridge Trust.

Last month, a senior lawyer warned that if Johnson was found to have pushed through decisions that led to a significant increase in the losses, he could face a potential investigation for misconduct in public office.