The Advertising Standards Authority (ASA) will soon be able to act on complaints about content and advertising on UK websites.

Proposed changes to the Committee of Advertising Practice's (CAP) code will extend the independent advertising regulator's power to cover content on companies' websites.

Anyone who thinks an advert is misleading or offensive or in breach of another of the CAP Code's provisions can complain to the ASA, which adjudicates all complaints that fall within the Code's remit.

The ASA receives around 2,000 complaints about website content each year, but the regulator is unable to act on website content "except sales promotions and advertisements in paid-for space".

This means that, for example, banner ads appearing on a newspaper's website are within the ASA's jurisdiction but promotions by that advertiser or company on its own website are not.

Winston Fletcher, the chairman of the Advertising Standards Board of Finance (Asbof), which raise the funds from advertisers needed to run the ASA, said: " At the moment marketing on websites is totally unregulated – they are outside of the ASA's remit.

"The changes we are working on will extend the CAP Code and bring websites the ASA's remit."

He said sanctions are usually unnecessary because once a company has been informed about a problem it usually makes the required changes.

“But we can impose sanctions. This rarely happens but it can result in advertising space being denied to an advertiser or if the breach is serious, we can refer it to the Office of Fair Trading,” he said.

Full details of the proposals will be published once they have been approved by CAP, The Advertising Standards Board of Finance, the ASA Council and the Advertising Association, whose Digital Media Group undertook the original work on the remit extension.

It is anticipated that the extended remit will come into operation during the second half of 2010.