The group wants the New Zealand Transport Agency to approve funding for two twin-lane bridges, which could cost $15 million.
It has written to all MPs emphasising the need for urgent replacement of the bridges on State Highway 82.
They also sent to each MP a copy of a bumper sticker saying: No Bridge No Vote.
Mr Coles said the existing 130-year-old bridges were increasingly closed during high river flows and for urgent repairs or maintenance.
In February, they were closed for 10 days, causing major disruption to communities living in the area.
The economic and social costs were huge and were something no community should have to endure.
Two public meetings have been held calling for urgent replacement of the bridges. A meeting in February was told work would start next year and be completed in 2014.
A meeting earlier this month, chaired by Mr Coles, was told the bridges were under daily monitoring and repair work was continuing to take place, causing more frequent closures.
"Surely, the need for this daily monitoring and the considerable financial costs involved with constantly repairing these bridges strengthens the argument for the speedy approval of funding of this project," Mr Coles said.
The agency's chief executive, Geoff Dangerfield, indicated the new bridges would be constructed by 2014-15, with funding yet to be confirmed in the 2012-15 National Land Transport Programme.
Mr Coles, on behalf of the affected communities, wanted an affirmative response to the funding as soon as possible.
The public meeting earlier this month decided that if funding was not approved before the general elections, those present reserved "the right to vote accordingly".
