It was formally signed by the UK Government and the region's five metropolitan borough councils (Bradford, Calderdale, Kirklees, Leeds and Wakefield) and after a public consultation on the deal, it became law in January 2021.

The deal is the biggest of its kind and transfers decisions about investment in transport, skills, housing and regeneration from Parliament to West Yorkshire.

The Local Government Act 2000 allowed all councils in England and Wales to consider a range of options as to how to amend or retain how they operate their executive functions, including the option for a local authority to be led by a directly elected mayor, instead of an elected councillor selected by their fellow councillors.

[4] As pledged in the 2010 Conservative Party election manifesto, the Conservative-Liberal Democrat coalition government held a series of local referendums on 3 May 2012 asking whether each of the twelve largest cities in England by population should have a directly elected mayor to lead their council.

"[14][15] The Cities and Local Government Devolution Act 2016 legislated for the election of new mayors to combined authorities across England and Wales.

As no deal had yet been agreed with West Yorkshire, it set out the legal framework for any future mayoralty with the devolution of some powers to West Yorkshire over education and training, economic development, housing and transport subject to the progression of future negotiations.

The model would have included the five West Yorkshire council districts as well as Barnsley, Craven, Harrogate, Selby and York.

[18][19][20] The proposed devolution deal was formally signed on 12 March 2020 in the Nexus building at the University of Leeds.

The agreement was signed by Chancellor Rishi Sunak, Northern Powerhouse Minister Simon Clarke, the combined authority's chair and Bradford Council Leader Susan Hinchcliffe, and the four other constituent council leaders: Judith Blake (Leeds), Denise Jeffery (Wakefield), Shabir Pandor (Kirklees) and Tim Swift (Calderdale).