Counties including Devon should have a "metro mayor" as the political figurehead for a massive devolution of powers from London, a leading think-tank has said.
The IPPR think-tank's vision for 40 different functions of government to be handed to the regions, including greater powers to vary taxes, was published as the Scotland independence vote sparked calls for decentralisation across the UK.
Deputy Prime Minister Nick Clegg said the Scottish debate had "re-energised people's interest and engagement in politics", and underlined the need for greater decentralisation of power within England.
The IPPR report, backed by Mr Clegg, identifies powers and budgets that could be ceded from 13 different Whitehall departments.
If adopted, its 10-year plan would lead to a new wave of combined authorities, as pioneered in Greater Manchester, with the possibility of directly elected "metro mayors" for regions.
IPPR makes clear the plan would not be limited to major cities, meaning it could be appropriate for largely rural counties such as the far South West.
It says a "metro mayor" could apply to any single local authority boundary.
It says: "There is a particular opportunity for counties and districts to enhance their relationships, such that rural areas and other towns and cities can enjoy the benefits that decentralisation might bring."
How powers were divided in the Westcountry would prompt fierce debate.
The South West Regional Assembly, based in Taunton and written off as a "talking shop", was supposed to be a pre-cursor to a fully elected tier of Government before Labour's devolution agenda was killed off by a "no" vote in the North East.
However, the Conservative Communities and Local Government Secretary Eric Pickles cautioned against calls for the creation of powerful new combined local authorities centring on big cities.
In his speech, Lib Dem leader Mr Clegg said the time has come to push for action on decentralisation.
"You only need look at how the Scottish referendum debate has re-energised people's interest and engagement in politics over the last few weeks to see that this is an idea whose time has come," he will say.
"Over the last decades, we've seen a wave of new powers shifting out to every nation of the UK, except England.
"With a new consensus now emerging amongst the UK's three main political parties to extend devolution and decentralisation in the future, I believe we can push forward in realising our ambitions for a stronger, fairer Britain."
IPPR calls for fiscal devolution to be a central plank of the 2015 comprehensive spending review, with five-year funding settlements agreed and an independent body established to take forward further central-local funding reforms.
The plan could eventually lead to property taxes and business rates being devolved to combined authorities and, eventually, a proportion of income tax being assigned to them.
IPPR North director Ed Cox, said: "Whichever way Scotland votes next week, Edinburgh will get new powers and widen the gap with local leaders across England.
"England has waited patiently while Scotland, Wales and Northern Ireland have been given ever great devolution. Now is the time to redress the balance and devolve powers to English city-regions."
Mr Pickles said that while there was "real scope" for further devolution of power in England, he questioned whether the creation of combined authorities was the right approach.
"Localism in England should be about devolving power to the lowest appropriate level – down to councils, to neighbourhoods and to individuals," he said.
"There may be some role for combined authorities on a strategic level to promote economic development and transport, but there is a real risk they will suck power upwards away from local councils and local taxpayers."
The Lib Dems this week promised "devolution on demand" in their election manifesto.
