About 7,500 people have now signed a petition on the Downing Street website calling on the government to scrap tolls on the Humber Bridge.
Campaigners want ministers to cancel the bridge's £333m debt
The online petition closes on Wednesday but campaigners vowed to keep fighting for the charges to be abolished.
Protest group Humber Action Against Tolls (HAAT) says they adversely affect the local economy and hit motorists who have to regularly use the crossing.
A HAAT spokesman said the campaign would be stepped up during 2008.
No 'magic' solution
Campaign organiser Jenny Walton said she was confident of success eventually.
"It will happen but it will take a while," she said.
"We have been working on this for four and a half years and we do not see everything all suddenly magically happening.
"We are working with MPs and councillors, all of the people who have clout.
"They need us to keep the awareness going and we need them to push the right buttons."
The Humber Bridge Board, which manages the structure, has itself has called on the Department for Transport to agree to a "payment holiday" of several years on the structure's £333m debt.
Bridge master Peter Hill said tolls could then be cut significantly because 80% of its income went on debt payments.