CAMPAIGNERS will today present their case for throwing out the controversial Tunnels Bill at the House of Lords.
A panel of independent lords will hear evidence from the Mersey Tunnels Users Association, which has dubbed the Bill a tax on commuters.
The private Bill would give Merseytravel the power to increase tolls without holding a public inquiry.
The committee will meet this morning and the hearing could last up to three days.
A spokesman for the association, which has more than 4,600 members, said: "We will be putting a very strong case to the committee which demonstrates that this Bill is simply not needed for the upkeep of the tunnels.
"On Merseytravel's own figures the tunnels are already self-financing and the prospects are that they will go even further into profit as debts are reduced.
"The tunnels collect more than £30m a year in tolls yet the Wallasey Tunnel cost less than £40m to build. The figures speak for themselves.
"In the Bill, Merseytravel say they would use surplus tolls revenue to fund public transport.
"But that is a burden that is not placed on road users elsewhere. It would simply be a tax that would hit the residents of Wirral hardest and that is wrong.
"If Merseytravel wants to finance and encourage the use of public transport then they should have the courage to propose a congestion charge for the whole of Liverpool.
"We believe that we can convince the House of Lords Committee that our arguments are sound, common sense.
"We recognise that it's a David and Goliath battle, but we are determined the oppose the injustice of this Bill."
The tunnels have been in profit since 1992 but Merseytravel wants the power to be able to use surplus money to pay for other public transport schemes on Merseyside.
The Bill passed through the House of Commons at the end of October and was expected to go through the House of Lords unopposed.
Lord David Hunt of Wirral stepped in to register his opposition at a crucial point in the proceedings, preventing it from progressing straight to the second stage.
Instead the reading was delayed until today to allow him to prepare his case for the opposition.
The campaign against it rests on how the presumption that, once the cost of building the tunnels had been paid off, then they would become free to use.
The committee has the power to drop the bill or alter it before it is passed on to its third and final reading.
Merseytravel has prepared a 500-page dossier for the committee and will be calling experts, including travel consultants, to give evidence on their behalf.
A spokesman for Merseytravel said: "We are confident of our case. We will now just wait and see what the lords have to say."