The evidence that the people of Northampton wants a West Northamptonshire Council needs to be revealed, the town's Labour group has said.
It comes after the Secretary for State announcement on Tuesday confirming that the county will get two new super-councils that will replace Northampton Borough Council in 2021
Northampton Labour group say they are relieved a decision has finally been made but believe Northampton needs to be a unitary on its own.
And group leader Councillor Danielle Stone (Lab, Castle) said the minister James Brokenshire needs to back up his claims that residents support his decision.
She said: "The decision talks about reviewing all the evidence from the public consultation. Well I would like to know what that evidence was, as it has yet to be published."
Mr Brokenshire, in his written statement laid before Parliament, referred to percentages of respondents to a telephone survey without revealing the actual numbers of people who agreed with his decision.
He also revealed that less than half (44 per cent) of the 6,000 people who answered the separate questionnaire wanted the two-unitary solution that will now be imposed.
His statement reads: "Ninety per cent of respondents to the telephone survey agreed that there was a need to make changes to Northamptonshire local government and 74 per cent agreed with the unitary proposal.
Eighty-three per cent of the over 6,000 individuals who responded to the open questionnaire agreed that there was a need for change, with 67 per cent agreeing that a number of unitary councils should be introduced and 44 per cent supporting the proposal for two unitary councils."
Councillor Stone said the year's delay in vesting the new authority will hopefully allow the new authority to be better prepared. But she said the gap had a downside.
She said: "We will use the extra time to fight for the ever diminishing services to be maintained for the people of Northampton but it’s an uphill battle.
"In the extra year the borough, the county and the shadow authority will all be running at the same time, with only the shadow authority have an elected mandate but no actual authority!
"Is the cost and confusion worth the estimated £44 million?"