Transport for London are being told any public money spent on London Mayor Boris Johnson 's Garden Bridge should be refunded, after a motion for the request was agreed in a City Hall meeting.

The London Assembly called for the mayor to promptly address the issue relating to the project, with a motion agreed by 12 out of 19 assembly members.

Liberal Democrats Mayoral candidate Caroline Pidgeon, who proposed the motion, said: "The latest discovery is that even before Transport for London had invited companies to submit their design bids for the bridge, the mayor was flying around the world at taxpayers’ expense to promote one specific design.

"It is time that the full facts over the procurement of the design contract were finally revealed.

"In the meantime not a penny more of public money should be poured into the project and every attempt should be made to recover any public money already allocated.”

Assembly member Tom Copley added: "If the Garden Bridge is to go ahead it must be done properly.

"That means a free and fair procurement process and transparency about the mayor's role.

"Questions remain over the procurement process, which undermine support for the Bridge to the extent the Royal Institute of British Architects are now calling for the project to be halted.

"Given all of this, I can't see how the bridge can go ahead."

In the London Assembly meeting on Tuesday (February 2), members expressed their concern over the news that the Mayor described a publicly funded trip to San Francisco in early February 2013 as "merely a private trip."

Eyebrows were raised after Boris was found seeking sponsorship for one particular design when TfL had not even started the process detailing the design of the bridge.

The announcement was also made by the Assembly that there is no case for any TfL funding to be allocated to the Garden Bridge Trust and discussions must take place to make sure all public money allocated to the project is "quickly recovered."

In January, Ms Pidgeon said in a speech she will halve the fares for all morning commuters by scrapping the Garden Bridge.