Many East of England businesses are unaware they are breaking the law when they fix or discuss prices with competing bidders when quoting for work, a survey has shown.

The Competition and Markets Authority (CMA) has launched a national cartel awareness campaign to educate firms about illegal practices as research showed a startling lack of knowledge about competition law.

It is urging people to come forward if they suspect a business has taken part in cartel behaviour, such as rigging contracts.

Its regional research found only 44% knew that fixing prices could lead to imprisonment, and nearly half either didn’t know or thought it was legal to discuss prices with competing bidders when quoting for new work. 63% didn’t know or thought that dividing up and sharing customers with rivals was legal.

CMA’s Jason Freeman said non-competitive deals with competitors was unfair to customers.

“It’s important that businesses in the east take the time to understand what the law says and how to comply – the repercussions of falling foul are just not worth the risk,” he said.

The campaign is targeting industries including construction, manufacturing, recruitment, estate agents and property management and maintenance, which have been identified as particularly susceptible to cartels.

Previous campaigns have driven a 30% rise in the number of tip-offs to the CMA’s cartels hotline.

Since April 2015 the campaign has issued more than £155m in fines following investigations into anti-competitive practices and it is currently investigating 15 cases including in construction services, roofing materials and estate agency.

Businesses found to have been involved in illegal cartels can be fined up to 10% of their annual turnover. Individuals can face up to five years in prison and directors can be disqualified from holding director positions for up to 15 years.