London's mayor is threatening legal action against a council which wants to suspend some of its bus lanes.
Residents say bus lanes have made traffic worse
Ealing is to scrap the lanes and enforcement cameras in Yeading and Northolt in west London for 18 months, to see if they are really needed.
The Tories, who were voted in at the recent local elections, said it was responding to complaints from residents who claimed they increased congestion.
But Transport for London said the move was "retrograde and anti-commuter".
"We have to consider the transport implications for the city as a whole and cannot agree to an approach that ignores these concerns in favour of a piecemeal approach," a Transport for London (TfL) spokesman said.
"The mayor will now consider all options, including legal and financial options, arising from Ealing's retrograde anti-bus announcement.
"This is an anti-commuter, anti-public transport announcement that does not seem to consider the needs of bus users."
The bus lanes to be removed are the ones managed by the council, in Yeading Lane, the section of Church Road north of the A40 and the adjoining Mandeville Road.
A request will be made to Transport for London (TfL) to remove the bus lane it manages in Church Road, between the White Hart and Target roundabouts in Northolt.
Ealing Council's leader Jason Stacey said the evaluation will also involve studies on pollution and safety.
"We have had so many complaints and seen so much anger and bitterness towards these bus lanes from residents since they were installed," he said.
"At least now we have the chance to see if we can live without them and whether they have actually made congestion worse. In effect what we have now is one big 18-month consultation.
"We will be totally open about what we decide after the 18 months is up and if it appears the bus lanes are needed, then we'll keep them."