Opposition councillors at Mid Suffolk seem likely to vote against moves to build a new northern route across Ipswich – and are warning that the consultation launched this week gives insufficient information to residents.

Green Party councillor Andrew Stringer, who is a member of both Mid Suffolk and the county councils, said he had been told by officials that any new route would require the construction of 15,000 new homes on its route for an economic case to be made.

He said: "This is far more than is in the current local plan, and we think people need know exactly what the options mean before they can make a real decision.

"We don't see how when we are trying to create a greener world it is good to build a road like this with thousands of new homes linked in to it."

The opposition and the Conservative-run administration at the council have the same number of councillors - the Tories are kept in power by the chair's casting vote.

However the proposed new road could have a major impact in some Conservative-held wards, and their councillors may be unable to support it - prompting the council as a whole to oppose the scheme.

One Conservative councillor whose voters would be affected by any of the proposals is Suffolk Police and Crime Commissioner Tim Passmore, who represents the Claydon and Barham Ward.

He said: "I am certainly urging people to go along to the consultation events and to find out all they can about these proposals.

"There is a need for improved road links to prevent congestion in Ipswich and also to ease the situation when the Orwell Bridge is closed by an accident or because of high winds.

"To that extent it is really a strategic solution that is needed and there may be a need to look at other solutions as well - maybe a tunnel alongside the bridge. I don't know if that is feasible."

The consultation starts on Friday and continues until September 13. There are number of exhibitions around the area during July and Suffolk County Council has set up a dedicated web site to give information about the road proposals.

The consultation document does say the road would "enable the delivery of around 10,000 to 15,000 additional homes across Suffolk," but it does not say they would be on the route itself.