London mayor Sadiq Khan today hired the formidable former chair of a Commons spending watchdog to investigate the Garden Bridge project.
Dame Margaret Hodge MP will examine whether the £185m scheme is value for money.
Taxpayers are contributing £60m in loans and grants to the tree-lined Thames crossing in central London.
Dame Margaret, Labour MP for Barking, east London, won a reputation as a tough inquisitor during five years as the no-nonsense chair of the Commons Public Accounts Committee.
Opponents of the Garden Bridge have attempted to halt the project with petitions, protest and judicial reviews.
Construction work is on hold until a final agreement on land ownership on the South Bank is negotiated.
City Hall sources insisted the project was not in doubt but the mayor would review Dame Margaret's findings with a 'fine tooth comb'.