A new legal weapon came into force over the weekend in a government crackdown on unscrupulous companies that mislead customers or use aggressive sales tactics.

The changes, which the Government claims represent the biggest attempt to tackle unfair sales practices in more than 30 years, introduce a new blanket ban on unfair trading, the first of its kind in the UK.

The Consumer Protection Regulations also bring together 23 existing laws, which Trading Standards officers have used against cowboy builders, rogue traders and unscrupulous salesmen in the past. However, the new regulations, which could lead to unlimited fines or lengthy prison sentences, will be much easier to enforce.

A total of 31 trading practices are now specifically outlawed under the new legislation, including aggressive doorstep selling and bogus closing down sales. The Department for Business, Enterprise and Regulatory Reform estimates that about 750,000 businesses will be affected by the new legislation.

Gareth Thomas, Consumer Affairs Minister, said: “These new regulations will deliver better protection for consumers, cut red tape and put in place a simpler and clearer consumer law that will be easier to interpret and enforce.”

The Government is investing £7.5 million training new trading standards teams to enforce the new regulations. A wide range of sanctions are available to officers from both Trading Standards and the Office of Fair Trading, including the power to take companies to court.

However, the legislation has been criticised by some consumer groups for not going far enough. The National Consumer Council (NCC) has pointed out that similar laws introduced in Ireland have included a mechanism allowing consumers to take legal action against companies found guilty of illegal selling practices.

Carl Belgrove, senior policy advocate at the NCC, said: “These new laws represent a big boost to consumer protection, particularly for vulnerable people who are targeted by rogue traders. However, the one thing missing is a way for consumers to claim compensation when businesses act unfairly and we hope that will be remedied soon.”

The new regulations, which were approved by MPs in April, apply to all businesses that trade directly with consumers, from car salesmen to builders. About six out of ten consumers fear that they are likely to be treated unfairly by tradesmen.