Ministers have vowed to press ahead with plans to name Birmingham City Council leader Mike Whitby shadow mayor of the city despite objections from the local authority.

The council has written to Ministers asking them to think again over plans to turn council leaders in England’s biggest cities into powerful shadow mayors at the end of the year.

It warned that the proposal could be considered undemocratic.

And the council also attacked plans to allow a directly-elected mayor to overrule councillors.

But the Government is to press ahead with the policy – and will even consider extending it to smaller cities. In theory, that could mean Wolverhampton or Worcester are asked to appoint a mayor.

Ministers announced last December that they would hold referendums in May 2012 in England’s 12 largest cities, including Birmingham and Coventry, asking residents if they wanted a directly-elected mayor.

If residents vote “yes” then an election for a mayor will be held in 2013. But in the meantime, existing council leaders will become shadow mayors this year, without a ballot.

The concerns raised by Birmingham City Council emerged as a Commons committee considered the Government’s Localism Bill.

The authority wrote to the committee, which includes Ministers from the Department for Communities and Local Government, attacking plans to give city mayors the power to force policies on councillors.

A memorandum from the council said: “This provision would have the effect of requiring the mayor’s proposal to be accepted unless the authority passed a resolution of two thirds majority voting against the proposals.

“This is considered by members as being undemocratic.”

It also attacked proposals to turn existing council leaders into what the Government calls shadow mayors without an election.

The council said: “From an operational and, perhaps, democratic point of view, it would make more sense to avoid making changes to constitutional documents if the executive leader remained an executive leader – instead of a shadow mayor – until any elected mayor was duly elected for the relevant authority.”

But ministers rejected calls to make changes during the committee hearing.