The code, developed with the Institute of Credit Management, was launched by business secretary Lord Mandelson at a prompt payment summit attended by companies including Asda, John Lewis Partnership and British Gas.

Businesses that sign up to the scheme, which is available online, are required to follow different procedures to existing schemes such as The Better Payment Practice.

The aim is to establish a clear policy in paying bills with a facility to raise concerns about late payers.

Lord Mandelson said: "It is critical we understand what payment issues are affecting small businesses and this summit will give us greater insight into the situation at ground level. The prompt payment of bills is an economic imperative and crucial if we are to protect supply chains from collapse."

Mark Snee, managing director of Technoprint, said: "The government has to make statements like this and the sentiment is right. There's no reason why big companies should be making late payments."

He added: "It would be interesting to see what would happen if a statutory interest rate on late payments was introduced."

Andrew Brown, corporate affairs director at BPIF, said: "If the print is being supplied through a print management company, it's important that they also pay promptly any company doing their printing.

"Otherwise it's the print management company that benefits because it effectively gets extra credit."

He added that end buyers must put pressure on their intermediaries to make sure payment happens on time.

Central government recently committed to paying its suppliers within 10 days.