Norfolk county councillors have narrowly backed proposals to establish a new combined authority for it and neighbouring Suffolk.
Members voted 34 to 28 to support the authority signing a new devolution agreement, and for the scheme to go out to public consultation, at a meeting in Norwich today.
A seven-week public consultation is now expected to start next week with a final decision on whether the county signs up to be made in October.
Council leader Cliff Jordan said it was vital the public was given its say on the deal.
He tried to reassure members they could still reject the deal in the autumn and vowed that he would do so if residents were opposed to it.
But he insisted questions about the structure of the authority, including that of a directly elected mayor, should not be the primary concern.
He said: “It should be about what’s in it for the people of Norfolk.”
But many of his political opponents said that, while they supported the principle of devolution, they could not back the current proposals.
Labour’s Terry Jermy dismissed the consultation process as “window dressing”, saying: “We’re not asking the public their views. We’re telling them what we have and asking them to support it.”
UKIP leader Toby Coke said warnings from central government that no other deal was available should be rejected in the light of the EU referendum result.
He said: “The threat from government that it’s now or never should be treated with the same contempt as Osborne’s threat of an emergency budget.”
Liberal Democrat Dan Roper, a former deputy leader of the council, warned the mayoral plan risked unraveling the whole project, while his colleague David Harrison suggested the money proposed could be spent through existing structures.
Green Andrew Boswell said the proposal’s focus on accelerating economic growth with little focus on the environment was “utter madness.”
And independent Alexandra Kemp said people in her division were “horrified” by the prospect of additional tiers of government.
But Conservative backbencher Barry Stone insisted the authority had be progressive and accept the deal.
He said: “If we don’t move forward, we’ll be doing the public a disservice. We could force the county into poverty, as against prosperity if we take the deal.”
Earlier, business leaders called on the counties’ councils to endorse the proposals.
Mark Pendlington, chairman of the New Anglia Local Enterprise Partnership, said: “We believe this is an opportunity none of us can afford to let pass.
“The result of the EU referendum and the uncertainty it brings means it is all the more important to seize the opportunity presented by devolution.
But North West Norfolk MP Sir Henry Bellingham said the deal should be withdrawn, because of the formation of a new government after the exit vote.
He also repeated his call for councils including West Norfolk, which will consider the plan on Thursday, to reject it.