Further pressure may be applied at New Zealand First leader Winston Peter's election meeting in Tauranga today.
City councillor Bill Grainger planned to ask if Mr Peters could use his leverage as a potential election kingmaker to do a deal and take the burden off ratepayers for the road widening.
"Things happen in an election year," Mr Grainger said.
He was referring to past successes including the U-turn three years ago when the Government agreed to take ownership of Route K, wiping $60m of debt off the council's books.
The first hint that the Government was looking to pay more than its standard half share of major council roading projects came when Welcome Bay resident Hori BOP Leeming spoke to the council's transport committee on Monday.
Mr Leeming said he had been given a "very receptive ear" at a recent meeting with Mr Bridges.
"They want it resolved as much as I do . . . I think the funding will be available if you talk to the right people."
Mr Bridges said he agreed with the views of Hori BOP. "We have got to keep working through the stages and finish the job."
Quizzed on whether the Government would fund the total cost of the new bridge and widening, Mr Bridges said: "By rights the council should be involved in some of the funding but there may be room to move on the Government side . . . let's see what the situation is once the underpass is finished."
He said the Government's $230m interest-free loan to the council for housing infrastructure announced this week would give the council headway on projects such as a museum and some roading issues.
The issue was lightly touched on when Mr Bridges met councillors on Tuesday. Transport committee chairman Rick Curach said that while the 2008 election pledge was not specifically mentioned, Mr Bridges spoke very positively about project costs.
"I took it very positively."
Mr Grainger wanted to make the 2008 pledge an election issue because it was made blatantly clear that the bridge and four-laning would be funded by a National-led Government.
"They promised the total project."
The timing of the four-laning will be decided when the council reviews the city's 10-year plan. Mr Curach said it would be dramatically brought forward from its current construction timetable beyond 2025.
In the meantime, interim traffic relief proposals along 15th Ave and Turret Rd would soon be coming to the council for approval to help cope with even more pressure on the corridor once construction began on the Baypark to Bayfair roading project and motorists avoided the Harbour Bridge route to town.
Mayor Greg Brownless said any movement by the Government to honour the 2008 commitment would be fantastic. ''The sooner the better - we can't wait too much longer.''
Progress so far on Tauranga's central roading corridor upgrade
Original budget for total project: $100 million
Early stages of the project: $20 million
Welcome Bay underpass: $45 million
Completion of underpass: April 2018