The government has been urged not to overlook English shire counties in its bid to “level up” economic performance across the UK.
County council areas had seen much lower levels of investment than London and other large cities, the lobby group representing them says.
The County Councils Network also called for councils to be given more power and control over local spending.
Ministers said they were committed to driving economic growth across England.
The County Councils Network represents 36 local authorities in mainly rural areas across England, including large administrations such as North Yorkshire and Nottinghamshire county councils.
Most big cities and built-up areas tend to be run by unitary authorities.
The network says in a report that economic growth in the areas it represents has lagged behind metropolitan areas.
Their call comes ahead of next week’s Budget, the first since the Conservatives returned to government after December’s general election.
Support in traditional Labour seats located in former industrial areas or in the shadow of bigger cities is credited with delivering the party’s 80-seat majority.
And government ministers have repeatedly insisted they want to “level up” - jargon for helping economically-weak areas catch up with more prosperous parts of the country.
The County Councils Network said more rural local authorities could play a “huge part” in the success of the government’s plan, but needed “powers and resource”.
Conservative councillor Barry Lewis, the group’s economic growth spokesman, said his party needed to avoid a “narrow focus” on areas that delivered its election success.
“Since the general election, there has been a clear focus on the ‘red wall’ seats that the government has won,” he said.
“But if it wants to genuinely back up its rhetoric and level-up England, then a narrow focus on these areas will not work. The levelling-up agenda cannot bypass and forget about shire counties.”
In its report, the group said per-person investment in county council areas was 50% less than London boroughs and 35% less than in other large cities.
It added that spending on multi-billion pound growth schemes was also higher in urban areas, with counties receiving £437 in funding per person compared to £580 per person in England’s larger cities or £537 in smaller cities and urban metropolitan areas.
The government has promised to improve performance in slower-growing regions through boosting skills and increased investment in transport projects.
Ministers are also considering re-writing Treasury rules to make it more likely that projects in such areas will get funding approval. Regional leaders have complained that current Treasury rules skew investment towards areas where growth is already high.
The government said it had recently begun discussions about devolution deals for Sheffield, Leeds and other cities in Yorkshire and would take councils’ views on board as it considered further plans for all the English regions.
“The levelling-up agenda is about scaling up our ambition and moving the country’s centre of gravity and economic focus away from London, driving local growth and delivering opportunity across the UK,” a spokesman said.
“We’ve already made great progress taking forward devolution and job creation with 37% of people in England now served by directly elected city region mayors and falling unemployment levels in every region since 2010.
“We also delivered more homes last year than in any of the last 30 years.”