The Countryside Alliance said rural communities and businesses would suffer unless the government's Broadband Delivery UK (BDUK) project was overhauled.
Its comments follow the publication of a hard-hitting report by the House of Commons Select Committee for Public Accounts criticising the rollout of rural broadband.
Alliance executive chairman Barney White-Spunner said the organisation had grave concerns about the BDUK project and BT's monopoly of 18 local contracts negotiated by the government.
"We feel the secrecy surrounding the final 10% of rural addresses that will not be covered by the scheme will hold back delivery of broadband to the countryside," said Sir Barney.
"Other arrangements cannot be made for these areas until it is known where they lie.
"The Committee for Public Accounts' report is welcome support for our concerns and, coming after the National Audit Office's criticism of the scheme in July, reintroduces an important debate.
Broadband had never been a more important tool for business, said Sir Barney.
But the delay in rollout and concerns about the ability of the BDUK project to reach all the countryside, meant rural businesses were at real risk of missing out.
The Countryside Alliance is also concerned that by delaying rollout of BDUK until 2017 the government will miss its own target of putting all key public services online by 2014.
A number of services are now online only – for example animal movement paperwork and HMRC – and are therefore unavailable for those without an internet service.
"The government needs to conduct a full scale review of BDUK, taking on board the comments made by the Committee for Public Accounts and the National Audit Office," said Sir Barney.
"The government should consider all technologies – including mobile phone technology – to deliver broadband to the countryside, not just fibre optic cabling."
The charity Action with Communities in Rural England said the countryside continued to suffer a raw deal in the 'piecemeal' roll-out of the broadband project across the UK.
ACRE chief executive Janice Banks said the burning issue for rural communities and businesses was as fundamental as whether they would get broadband or not.
"Many local councils have published maps for the rural broadband programme, which is meant to extend superfast coverage to 90% of the premises in the UK."
Information provided by some councils was so limited and inconsistent it was impossible for people to tell whether their homes and businesses were included or not, she claimed.
"This confusion ties the hands of innovative communities who want to come up with their own broadband solutions. No one will invest in a plan that could be overtaken by the BT roll-out.
"Defra's rural proofing guidelines say this government wants to be sure rural areas get a fair deal from all Government policy. We fear that, once again, rural communities are getting a raw deal.
Rollout plans should be published in a consistent and meaningful way so other solutions could be found to reach the remaining 10% of people who would still be without superfast broadband.
"This information needs to be available straight away, irrespective of the local authority area, so that communities and businesses can benefit from the broadband that their urban counterparts take for granted."