A launch event will be held in Leeds, where the body will announce £118bn of investment opportunities, including:

The six leaders joining McGuinness and Houchen are Tracy Brabin of West Yorkshire, Andy Burnham of Greater Manchester, Steve Rotheram of the Liverpool City Region, York and North Yorkshire mayor David Skaith, South Yorkshire's Oliver Coppard and Luke Campbell of Hull and East Yorkshire.

Cumbria and Cheshire & Warrington are in a devolution priority programme which envisages mayoral election in 2026.

Meanwhile, following the establishment of a Combined Authority in Lancashire, discussions are underway on establishing a mayor there too.