Internet service providers (ISPs) should be "obliged" to deliver speeds of 8Mbit/s to smaller firms, according to the Federation of Small Businesses (FSB).

An FSB survey of 1,289 small organisations found that 24 per cent are dissatisfied with the broadband service they receive from their ISP.

Around 63 per cent cited reliability and speed as key issues, while 30 per cent operate in areas with unreliable broadband connections. A further 13 per cent would consider moving premises for better speeds.

A spokeswoman for the FSB said that the figure of 8Mbit/s was based on previous research identifying it as the optimum speed for most small companies. She also criticised the Labour Party's broadband proposals.

"We think that Labour's proposed 2Mbit/s service lacks ambition. Most firms already have speeds of this nature and need more. To have a truly global broadband economy we need speeds that are useful to businesses for the future," the spokeswoman said.

She added that, while the FSB welcomed the Conservative Party's plans for 100Mbit/s upload and download speeds by 2017, something more realistic and reliable is needed sooner to spur economic growth.

However, James Blessing, chairman of the ISP Association's broadband sub-group, believes it unrealistic to imagine that ISPs could provide guaranteed speeds of 8Mbit/s across the country.

"People do not understand that, unless you are near the exchange, it is very hard to get the speeds that services are quoted as 'up to'. The ageing copper networks in the ground cannot provide the speeds people think they are going to get," he said.

Blessing added that many firms often sign up to what amount to residential services that cannot deliver the speeds they need.

"There is a lot of work being done in cities to create super-fast networks to offer better quality services for a higher cost, but many firms often to look to cut costs by using cheaper services," he said.