All "non-essential" road improvements in London have been paused because of a lack of funding, City Hall has announced.
It warned that the forthcoming loss of Transport for London's operating grant from the Government would have "obvious consequences".
Road schemes deemed "non-essential" have been suspended for two years "unless suitable funding can be found".
This could lead to a rise in disruption with increased road closures and speed, size and weight restrictions.
Latest figures from the Asphalt Industry Alliance's Alarm survey show 16% of the capital's roads are in a poor condition and £21.4 million is needed to clear the carriageway maintenance backlog.
The decision to remove TfL's operating grant was made in 2015 when Boris Johnson was London mayor.
This is equivalent to a cut of £700 million per year in Government funding over the next five years, City Hall said.
The mayor's office added that the Government has "unbelievably" decided that, from 2021, the £500 million raised every year through Londoners' vehicle excise duty will only be invested in roads outside the capital.
This means Tube and bus fare-payers are subsiding the cost of running London's roads, the statement said.
In a speech to members of the International Transport Workers' Federation on Wednesday, deputy mayor for transport Val Shawcross will say: "Our capital is the beating heart of the UK and our roads are the arteries, so it's just astounding that the Government is not only prepared to take away vital funding but make London's drivers pay for roads outside the capital.
"We've seen from the success of the Crossrail project how investment in London can benefit the whole of the country, and it's vital that the Government uses its spring Statement next month to reinstate TfL's funding and keep the capital moving."