London Mayor Sadiq Khan has commissioned a formal review of the Garden Bridge project.

The 367m long pedestrian bridge is to cross the Thames between Temple and South Bank and would be a ‘garden on the water”, containing an abundance of plants.

Sprouting from an idea by actress Joanna Lummley, the bridge has been designed by architect studio Heatherwick with Dan Pearson appointed garden designer and ARUP engineers on the scheme.

While the bridge will undoubtedly be an iconic addition to the London urban landscape and provide an important pedestrian link between the two banks of the river, the project has also been controversial. Construction is estimated to cost £185m of which £60m is supposed to come from public funding. Annual running costs of the bridge are anticipated to be £2m. Start on site has been delayed to at least 2017 and a crucial land lease is still to be agreed. There has also been a lack of transparency when Heatherwick Studios was appointed as architect under Boris Johnson, implying irregularities in the selection process.

The inquiry will be led by Labour MP Dame Margaret Hodge, who will look at the amount of public money spent proportionate to the benefits the garden bridge will bring. The main purpose of the review is not to make recommendations on whether or not to continue with the scheme, but its findings may well cause Sadiq Khan to reconsider the project in the light of Brexit uncertainty.