The Broadband Stakeholders Group is worried that the government will not support investment to roll out a 2mbps universal broadband service broadband to rural areas.
The supplier-led association welcomed with reservations the government's commitment announced in the Budget.
But it said it was concerned that the announcements "do not yet provide grounds for confidence that such services will be made available beyond urban areas".
The BSG said earlier it would cost close to £30bn to provide optical fibre to every house in Britain (FTTH), but just over £5bn if the fibre went to the street connection cabinet (FTTC). Most of this would go on civil engineering works in rural areas, it said.
Cities and towns are already well-served. The Information Commissioner's Office reported that most broadband subscribers received an average download speed of more than 4mbps, but the adoption rate, 15.6 million consumer connections, is relatively low at 26%.
BT has already announced plans to spend £1.5bn to provide access to 40mbps connections to some 10 million homes, and Virgin Media is nearing the end of its roll-out of 50mbps access to 12 million homes. Virgin Media CEO Neil Berkett told the recent Digital Britain summit that his network could be pushed to 200mbps.
These projects cover most urban homes. The government's proposed universal service obligation would bring country-dwellers online, but at 2mbps.
The government said it would also consider wireless access, which would provide high speed mobile broadband. Most of the five mobile operators are working on plans to install 100mbps networks based on Long Term Evolution (LTE) technology from next year.
They are also asking for the government to release frequencies in the 800Mhz range while the government is negotiating for Vodafone and O2 to give up some of their 900MHz frequencies.
These changes to spectrum ownership are likely to prove vital to getting high speed broadband to country area at an affordable price.