Lord Jim O’Neill, a key ally of George Osborne in efforts to empower the North, told supporters of “One Yorkshire” devolution they must demonstrate the economic benefits of a region-wide mayor and powers “rather than repeated focus on the marketing brand of the name Yorkshire”. In a warning to supporters of a pan-Yorkshire authority which include 18 out of 20 of the region’s councils, he said the economic rationale “remains unclear”. Sceptical Ministers will not approve a region-wide deal unless supporters bring forward “substantive reasons” that go beyond getting “excitedly noisier” about the prospects, he said. Yorkshire devolution: Detailed proposal sent to Government as 18 councils seek ‘historic’ agreement New Sheffield City Region mayor Dan Jarvis has made clear his desire to pursue a One Yorkshire deal, but South Yorkshire’s councils are split between backing his office or a wider deal. Lord O’Neill told The Yorkshire Post: “I am still yet to see a really strong, articulated and written justification as to what the actual economic benefits of One Yorkshire are and how it would be administered. “It is really imperative of those that keep talking with so much noise about One Yorkshire to actually get on and argue what are the reasons why this is so compelling, other than just going on about the brand and marketing because that’s pretty empty really. “And I know many out there say ‘well you just don’t get Yorkshire’, well what does that mean? “A sort of powerful self chest-beating slogan - but if you really want the Government at the end of the day to risk issues to do with the country’s national debt and hand over powers you’ve got to have something of substance.” Rachel Reeves: New Mayor is a first step on way to One Yorkshire A year on from the landmark election of metro mayors in the likes of Greater Manchester, the crossbench peer’s report for the Northern Powerhouse Partnership said bridging the Humber to include North Lincolnshire, as major businesses such as Associated British Ports (ABP) do, “would demonstrate that One Yorkshire is about economic benefits and not just tribal and regional loyalty.” Combined control of health could be “significant”, potentially playing “a preeminent role in supporting employment and growth across Yorkshire”, the report said. Not the end of Yorkshire’s devolution story, but the beginning: Dan Jarvis looks ahead after becoming Sheffield City Region mayor Lord O’Neill warned that York and Hull could break away from One Yorkshire to negotiate their own deals, creating a potential scenario in which Leeds and West Yorkshire end up with no devolved powers despite being at the front of the queue in 2014. Stressing he is “open to being persuaded”, Lord O’Neill added: “I hope now we’ve got a Sheffield City Mayor agreed and it looks like other places in the North are likely to go ahead, it will galvanise the fans of the One Yorkshire idea to get really specific.” He added: “We as NPP will offer to work with the proponents to make their case as strong as possible to answer the concerns the Government has raised.”