Boris Johnson will return to City Hall to answer further questions about the abandoned Garden Bridge project.
The former mayor of London will appear before the London Assembly in March after previously declining to take part in Dame Margaret Hodge's review.
A number of issues were raised by the review, including questions over the £200m project's procurement and funding.
Hodge operated as an independent reviewer paid by the current mayor, Sadiq Khan, and had no formal power to compel witnesses to take part in the review. Johnson refused to be quizzed by her but has now been summoned to City Hall by the London Assembly's Oversight Committee.
According to MayorWatch, Johnson will be grilled by the London Assembly on 1 March.
Committee chairman Len Duvall said he was "very glad" Johnson had agreed to appear.
"The former mayor did not participate in the Hodge review of the Garden Bridge Project and we believe only part of the story was told when he appeared before us in December 2015," he was quoted as saying.
"Dame Margaret did not have the power to formally require the former mayor to give evidence. However, the assembly does have that statutory power.
"We will ensure the foreign secretary has all the information he needs to be able to answer our questions on the day.
Great cost to the taxpayer
"It is important that he gives us a full and complete account of how so much money was spent on a project that was abandoned at great cost to the London taxpayer."
In August 2017, the Garden Bridge Trust, the charity behind the project, said plans for a new bridge across the Thames between Waterloo and Blackfriars bridges had been scrapped.
The decision came after Khan told Lord Mervyn Davies, the chairman of the charity, in late April that he was not prepared to sign the guarantee for the annual maintenance costs of the bridge, warning that it would "expose the London taxpayer to too much additional financial risk".
The trust had already spent more than £37m of taxpayers' money on pre-construction work.
"It is with great regret that trustees have concluded that without mayoral support the project cannot be delivered," Davies said.
"We are incredibly sad that we have not been able to make the dream of the Garden Bridge a reality and that the mayor does not feel able to continue with the support he initially gave us.
"We had made great progress obtaining planning permission, satisfying most of our planning conditions, and we had raised £70m of private money towards the project."