It comes as the charity Action with Communities in Rural England highlighted the need for future government policy to be 'rural proofed'.
ACRE says measures are needed to address the question of how EU investment will be replaced or replicated post-Brexit.
Rural areas have been major beneficiaries from EU funding under the Common Agricultural Policy – and other schemes.
RSN chief executive Graham Biggs MBE said: "Rural communities will be among those most affected by the UK's decision to leave the European Union.
"European funding has been crucial in helping many of our rural communities overcome the challenges they face – including rural isolation.
"Central government has historically and systematically underfunded our rural areas – despite the fact that it costs more to provide rural services."
"It is clear that the next government must deliver a fair deal for rural communities and the service providers they rely on."
Manifestos published by all three main political parties include a number of rural-related pledges ahead of the general election on 8 June.
The Conservative manifesto pledges to support community minibuses for rural areas poorly served by public transport.
It promises to "bring sustainable growth to the rural economy and boost our rural areas".
Doing so will ensure that people who live in the countryside have the same opportunities as those who live in our towns and cities, says the manifesto.
It adds: "We will also take steps to enhance the provision of public services in rural areas.
"We will safeguard the post office network, to protect existing rural services and work with the Post Office to extend the availability of business and banking services to families and small businesses in rural areas."
The Tory manifesto says it is "our ambition is that all routine small business and consumer banking services should be available in rural post offices."
And it pledges: "We will support pharmacies and village schools in rural areas."
The Labour manifesto accuses the Conservatives of taking rural communities for granted, with "chronic underinvestment in transport, broadband and public services, including the closure of local schools, post offices and libraries".
It says: "Rural infrastructure and industry has been neglected.
"Labour will invest in broadband, housing and transport to create jobs and ensure that the nation’s prosperity is felt beyond our large towns and cities."
Labour’s national investment plans include broadband and 4G extensions that the party says will underpin the future success of rural small businesses.
"Rural councils deliver public services differently, and this needs to be re?ected in funding allocation mechanisms," it adds.
"We will consider these differences in our re-evaluation of the business rate schemes.
"We will introduce a 'rural-proofing' process so that all our laws, policies and programmes consider their impact on rural communities."
The Liberal Democrat manifesto says a thriving rural community needs local services and community facilities such as schools, public transport, local shops, cultural venues and pubs.
"It needs enoughhomes, affordable for local families, to ensure those services are viable," says the document.
"Liberal Democrats understand the changes needed to support a living, working countryside."
The Lib Dem manifesto promises that every property in the UK is provided, by 2022, with a superfast broadband connection with a download speed of 30Mbps, an upload speed of 6Mbps, and an unlimited usage cap.
It promises to invest £2 billion in innovative solutions to ensure the provision of highspeed broadband across the rural UK.
The manifesto promises to work with local authorities and providing grants to help areas replicate the success of existing community-led projects.
The Lib Dems say they will set up a £2 billion Rural Services Fund of capital investment.
It says this will "enable communities to establish a local base from which to co-locate services such as council offices, post offices, children’s centres, libraries and visiting healthcare professionals".
The Lib Dems also promise to work with Ofcom to ensure that mobile phone companies provide fast and reliable coverage in rural areas.
The party says it is committed to preventing Post Office closures and protect Royal Mail’s Universal Service Obligation to deliver across the UK for the same price.
And it pledges to work with local authorities to deliver a significant increase in social and affordable housing in rural areas.
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