A series of planned Parliamentary boundary changes which included the controversial breaking up of the Sutton Coldfield constituency are far from dead in the water, city Tories and Lib Dems have claimed.

Deputy Prime Minister Nick Clegg threw the proposed changes into doubt this week when he said that the failure of backbench Conservative MPs to support reform of the House of Lords meant Lib Dems would no longer be keen to back the boundary plans and push them through before the 2015 General Election.

Prime Minister David Cameron has meanwhile pledged to plough on with the changes and hopes to pursuade Parliament to back him. Under the plans the number of MPs will be cut from 650 to 600 and their constituencies become roughly equal in population size, tilting an electoral advantage away from Labour towards the Conservatives.

Under draft plans issued last year Birmingham would lose one of its ten constituencies, probably Hodge Hill, and others would be carved up and, in many cases, straddle the city boundary.

The decision to move Kingstanding into Sutton Coldfield, while moving the Walmley and Wylde Green area of Sutton Coldfield into Erdington, prompted one of the biggest postbags of objections the Boundary Commission received over their plans.

But Birmingham’s only Lib Dem MP, John Hemming (Yardley), said that despite the apparent falling out, there is still a long way to go.

He said: “The reform of the House of Lords was directly linked to the boundary changes. Cutting the number of MPs would only give more power to the Government, that is why we wanted the House of Lords to take a more assertive role.”

He added that he expected several proposals, including the ‘‘ridiculous’’’ carving up of Sutton Coldfield, to be reversed or altered in the Boundary Commission’s final proposals.

And Birmingham City Council’s Conservative group deputy leader Robert Alden also said he hoped the changes would go through. He said: “David Cameron is right to carry on with this and explain that until changes are made each vote does not count the same. Constituencies should be the same size.”