A Senedd debate will today hear a call for the Severn tolls to be abolished once the bridges return to public ownership.
The move is broadly supported by all parties.
George Osborne announced at the Budget this year that charges for vehicles will be halved from 2018 when the two bridges return to public ownership.
Motorists travelling from England into Wales currently pay £6.60 for cars and £13.20 for vans.
VAT on the charges will be scrapped when the bridges return to public ownership.