Small businesses are more vulnerable than consumers to exploitation by energy firms and should receive helping in dealing with them, according to the British Chamber of Commerce (BCC).

The group has also called on the energy regulator Ofgem to explain why businesses have to sign long-term deals with companies whereas consumers can switch after just 28 days.

Companies were also bound by verbal contracts with immediate effect, the body added, while domestic customers were entitled to a "cooling-off" period.

"With the economy slowing and energy bills on the rise it is totally unacceptable that hard-pressed businesses are left so open to exploitation by energy suppliers," said David Frost, director general of the BCC.