The main political parties have pledged to review tolls on the Humber Bridge if they win power at the general election.
Business leaders have called for the tolls to be scrapped or reduced to £1.
Liberal Democrat Treasury spokesman Vince Cable told Hull Chamber of Commerce he was aware of concerns the tolls were damaging the local economy.
Labour said it had frozen the tolls and commissioned a study of their economic impact. The Conservative Party said it would carry out a similar study.
The tolls currently stand at £2.70 for cars, £1.20 for motorcycles and between £4.90 and £18.30 for goods vehicles.
Mr Cable talked to Hull Chamber of Commerce members during a visit to the city on Monday.
'No easy solution'
He said: "I will absolutely promise you that we will look very, very carefully at the economic studies and act on the basis of evidence.
"There is no point the government pursuing charges which actually not only pose problems for the area but actually produce less government revenue."
In October the government announced a £6m grant to cover maintenance costs on the bridge which would ensure a toll freeze for 18 months.
A Labour statement said: "As we set out in our manifesto for Yorkshire and the Humber, tolls on the Humber Bridge have already been frozen and work on a study on the impact of tolls on the economy will be complete in six months' time which will give us a robust evidence base on which to make a decision about the tolls."
A Conservative Party spokesman said: "While it is true that the state of the public finances means that there are no easy solutions here, we believe that it is vital to look at the whole issue in the round and carry out a thorough investigation of the facts.
"While the pressure on the public finances means we cannot make commitments at this stage on the long term future of the tolls, what we can promise is to look seriously and carefully at all the options with an open mind and give the communities affected by the issue a fair hearing."