One of the most remarkable achievements of the Conservative-Liberal Democrat coalition responsible for running Birmingham City Council since June 2004 has been to keep a lid on, at least in public, disagreements between the two partners.

But the ease with which council leader Mike Whitby has pursued his liberal-Conservatism may be coming to a messy end.

The splits beginning to emerge among Conservative councillors are, in part, the result of success. The Tory group is now 49-strong and the party is picking up seats in formerly strong Labour areas. This has ushered into the Council House a number of young, ambitious, right-wingers who have joined forces with older, more cynical and disillusioned members with an axe to grind.

The result is the formation of a potentially explosive cocktail of Conservatives who, as they see it, are marginalised by Coun Whitby and his cabinet colleagues, kept in the dark and banished from policy-making.

Two issues have brought this rebellion to a head. The announcement by Coun Whitby at the end of last year that Birmingham may bring back the municipal bank, and the declaration last week by cabinet housing member John Lines that firms bidding for a council contract would be required to buy vans from LDV.

Neither proposal, it is said, was discussed in advance by the Tory group. Right-wingers see the bank as a waste of money, serving only to throw taxpayers’ cash at bad debtors, and regard Coun Lines’ scheme as unenforceable socialist protectionism of the worst type.

Demands by the rebels are beginning to fly thick and fast. A rowdy Tory group meeting witnessed, it is claimed, the unedifying sight of Coun Lines shouted down, accompanied by requests for the establishment of a 1922-type committee to act as a powerful backbench voice.

Anyone who knows anything about the real 1922 Committee will be aware this is a group that the likes of David Cameron ignore at their peril. The men in grey suits have the power to make or break party leaders – and have often demonstrated they can do just that.

Coun Lines’ dismissive remark, that the trouble is simply being whipped up by a few “boys”, shows not for the first time that he doesn’t understand what is going on.

He and nearly all of his Tory cabinet colleagues have been in office for five years and the strain is beginning to show. It is time for Coun Whitby to show true leadership by bringing in new talent and refreshing his top team.

Failure to do so could prompt a right-wing revolution and threaten the very future of the coalition.