Birmingham and the West Midlands would have been fast-tracked to city region status if council leaders had agreed earlier this year to have a directly-elected mayor, a senior civil servant suggested last night.

John Edwards, chief executive of the regional development agency Advantage West Midlands, said former Local Government Minister David Miliband had made little secret of his desire for American-style mayors when discussing city region proposals with regional representatives.

Mr Edwards told a conference in Birmingham that Mr Miliband had said: "If you rolled over and said you would have a mayor you could have your city region tomorrow."

Mr Miliband was replaced in last month's cabinet reshuffle by Ruth Kelly, who has indicated that she will continue with her predecessor's policies on city regions.

The leaders of the seven West Midlands metropolitan councils and Telford & Wrekin Council, who are pushing for city region status, have rejected the idea of a directly-elected mayor.

They believe the city region, which would be given new powers to run regeneration, housing and skills, would be best led by an executive board of council leaders, representatives from Government agencies and the business sector.

Mr Edwards told the RegenWM city regions conference that AWM would work with whatever city region structure the Government approved. However, he sounded a number of warnings about the way the new structure might work.

He said: "We have to be clear about how decision making would work. Can we be certain we can secure agreement on contentious issues across the leaders of the local authorities making up the city region? Is this the most effective way of doing things?"

Mr Edwards also raised questions about the impact a city region might have on surrounding shire counties.

He said: "How would the city region add value? How can we show the city region could do things better than Whitehall can?

"We have to be able to demonstrate we can do all of this without excluding the shire towns and the rural areas.

"It makes no sense whatsoever for Government to say we are going to set our cities free if it is to the detriment of the remaining parts of our region.

"It is not enough to say that the wealth generated by the urban core will also generate wealth for rural areas. The trickle down theory doesn't really work. City regions have to accept their wider responsibilities.

"There is a danger in having this debate in the centre of Birmingham that we think of the city region debate as being entirely about Birmingham, the Black Country, Solihull and Coventry and we forget about the challenges facing Stoke and Staffordshire."

Nigel Pursey, the chief executive of Staffordshire County Council, warned the conference not to lose sight of the power of the West Midlands shire counties.