Labour and Liberal Democrat councillors are "calling in" the plans to Bath and North East Somerset Council's watchdog committee for more public scrutiny.
Lib Dem, Alison Millar, said: "Of particular concern is the huge public outcry which has occurred since the decision."
The BBC is awaiting comment from the ruling Conservatives at the council.
Last week, the council voted in favour of using a site on the west side of Mill Lane at Bathampton Meadows to build a new park-and-ride.
Hundreds of people have protested against the proposal, including the owner of the land who has said he will not sell-up to the council.
The official challenge to call in planning proposals is one of the powers opposition parties have to put cabinet decisions under further scrutiny.
If the challenge is upheld, the cabinet will be forced to reconsider its decision within 10 working days but if it goes the other way, the cabinet's original decision will be implemented.
An official challenge has been made to scrutinise plans for a proposed new park-and-ride site in Bath.