Chichester District Council will now formally request that a new consultation on improvements to the A27 around Chichester is carried out by Highways England.
The council says this should include a range of options, inlcuding the two northern bypass options that were previously dropped.
It also wants Highways England to publish the results of the consultation, held last year.
A letter to the Secretary of State will be issued.
Tony Dignum, leader of Chichester District Council, said: ‘This is not about the council favouring a particular option, it’s about the transparency of the process and public confidence in the preferred option.
‘In September, we requested justification for the decision to drop the northern bypass options.
‘Highways England responded to this a few days ago, but we are still no clearer on why the northern options were dropped.’
The government-owned company said its starting point for improvements on the A27 is through the longstanding proposals for a series of junction upgrades along the existing bypass.
It says this was in the government’s Road Investment Strategy and is reflected in the budget available to it.
It added that the only reason it communicated other options, such as a new bypass to the north, was to make sure that the reasons for ruling them out in the past are still valid today.