Each of the seven councils in the West Midlands Combined Authority (WMCA) is poised to take responsibility over a different regional portfolio.

With pressure mounting on Birmingham, Solihull, Coventry, Wolverhampton, Dudley, Walsall and Sandwell to introduce a mayor, the partnership has decided on a new option for power sharing.

Measures mean that when WMCA takes on its statutory powers in 2016, leaders and chief executives from each local authority will take charge of different portfolios - potentially including transport or economic development.

The news came after chancellor George Osborne used his Budget to welcome government progress on ‘pushing for more powers and responsibility to be devolved to the Midlands’.

Local government minister Marcus Jones last week told the Commons that the area would ‘certainly need a metro mayor’ if it wanted to put together a devolution package as ‘extensive’ as Greater Manchester’s.

He added the region now needed to ‘come forward and tell us the level of its ambition’ but it was ‘up to them’ to decide on whether they wanted a mayor.

‘We need governance and accountability so that powers can be exercised properly and effectively, for the benefit of all. Mayoral governance is an internationally proven model of governance for cities. Hence, as the chancellor has made clear, we will devolve major powers only to cities that choose to have an elected metro mayor, but the chancellor has also made it clear that we will not impose a metro mayor on anyone,’ Jones said.

‘We are determined to hand as much power as possible to places with a clear, strongly led plan. With their proposal, the seven west midlands councils are showing what can be achieved by working together to bring greater opportunity to their area. We look forward to working with them as they develop their proposals.’

Plans laid out by the WMCA early this month detailed a pledge to ‘create the most effective combined authority in the country in order to propel our economy to further growth than can be achieved at present’.

A WMCA spokesperson said: ‘The formal WMCA doesn’t come into effect until spring 2016. Before then it is a voluntary collaboration between local authorities. It has no statutory power until 2016.

‘But our model is based on distributed leadership with Wolverhampton supplying both the programme team and the clerk to the ITA. In recent discussions it's been decided the different chief executives lead on different portfolios as will leaders.’