Plans to redraw Northampton's constituency lines "do not have the town's interests at heart", says a former town MP.
A consultation is open until December 11 to shake up the boundaries of Northamptonshire's parliamentary constituencies - which decides who is the elected MP for an area.
It means Northampton town centre will be joined with around a dozen rural villages under the new proposed Northampton South boundaries in 2018.
The redesign is part of a national plan to ensure every constituency in England is made up of the same number of residents of around 75,000 people.
But former MP Sally Keeble says this will take focus away from the town centre at a time when it is "in dire need of regeneration."
She said: "The Northampton South MP [currently Andrew Lewer] will have to take responsibility for all of the urban town centre as well as huge areas of rural Northamptonshire.
"I can understand they want to rebalance the constituencies but this does not take into account how communities and towns work."
Under the new proposals, villages around the town like Great Houghton, Wootton, Milton Malsor, Gayton, Harpole will be made part of the Northampton South area.
It also means Abington, Weston Favell, Ecton Brook and Rectory Farm will join Northampton North.
Sally said: "One solution is to make a "donut" constituency to separate the rural and urban areas. Another, controversial solution could be to find a new way to split Northampton down in the middle.
"They also need to take into account the thousands of new houses planned for Northampton and rework the boundaries on where they're going to be.
"As it is, the new Northampton constituencies would not be beneficial to the democratic process.
"I would urge all of Northampton to make sure their voice is heard in this process."
To see the new constituency map and give feedback in the consultation, enter your postcode at the Boundary Commission for England website.