A county councillor has called for an inquiry into "unacceptably low" broadband access in Powys.
BT said more than 99% of people in Wales can access broadband
Richard Noyce, chair of Powys Council's economic and social development committee, said connection speed was a "major concern" for businesses.
He wants the committee to scrutinise the issue at a meeting next month.
British Telecom has said 99% of people can access broadband in Wales and it is working with the Welsh Assembly Government to improve the service.
Last month, regeneration group Mid Wales Partnership said black holes in rural Wales's broadband network were putting the area in danger of falling behind the rest of the UK
It called for "urgent planning and investment" to improve high speed internet connection.
Mr Noyce, a councillor in Newtown, said residents and businesses in the county were concerned.
He added: "While there are areas where the provision is adequate or good, there are still too many rural areas in which the provision is of an unacceptably low standard.
"This disparity of provision, taken together with the continuing concerns being raised about the actual speed of broadband provision, is of major concern to the economic and social development committee."
Mr Noyce said the committee would consider setting up a "full scrutiny investigation" next month.
Dai Davies of the Federation of Small Businesses, based in Newtown, said he shared the "frustrations" felt by a number of companies unable to take "full advantage of promoting their businesses" through broadband.
British Telecom (BT) said more than 99% of people in Wales could access broadband although a small number could not. It is working with the assembly government on the problem.
A BT spokesman added that all of the nation's phone exchanges were "broadband enabled", and more than 99% of people could access broadband services.
The Welsh Assembly Government said its regional innovative broadband support project was in talks with the telecommunications industry to "determine appropriate, cost effective solutions for providing broadband" in blackspot areas.