A bid to block powers contained in the new transport act as a way to avoid increases in Forth Road Bridge tolls has failed.
Authorities are planning for the bridge's future
The Conservatives had sought to restrict a scheme to give councils powers to fine drivers who fail to pay any future road congestion charges.
The party claimed its move would stall proposals to increase Forth Road Bridge tolls to as high as £4.
But Transport Minister Tavish Scott insisted the issues were not linked.
The possibility of tolls rising became a focus for campaigning in the recent Dunfermline and West Fife by election.
Holyrood's transport committee was considering the Transport (Scotland) Bill, already passed by MSPs.
Conservative MSP David Davidson tabled blocking amendments to try to stop the approval of variable tolls.
The act includes legislation enabling congestion charging, which is what variable bridge tolls would be.
Given that assurance of no link, MSPs on the transport committee rejected the Tory move by seven votes to one.
Bridge operators the Forth Estuary Transport Association (Feta) have proposed charges of £4 for cars crossing during rush hour, with a 50% reduction for cars with at least one passenger.
Mr Davidson has accused the Liberal Democrats of rank hypocrisy, having claimed to be against a price hike, while their councillors backed it on the bridge authority.
The National Alliance Against Tolls (Naat) welcomed Mr Davidson's approach.
Spokesman John McGoldrick said: "The Forth bridge tolls are due to end on 31 March and in the recent Dunfermline and West Fife by-election all of the parties gave voters the impression that they opposed the tolls."