Information Commissioner Richard Thomas has criticised the government's anti-spam legislation, calling on ministers to extend his powers to tackle unsolicited email.

The measures announced by the Department of Trade and Industry (DTI) will protect consumers rather than businesses, whose networks suffer a daily flood of bulk emails, nor cover anyone sending spam from outside the UK.

Those that are successfully prosecuted will be subject to £5,000 fines, levied by the Information Commissioner.

Experts have criticised the government's anti-spam legislation, and warn that it is putting too much responsibility on the overworked, under-resourced Commission.

And while Thomas (pictured) welcomed the move to control unsolicited emails, he called on the government to give him greater powers for tackling spammers.

"I am pleased at the DTI's commitment to review the enforcement powers of my office, but am disappointed that it has not been possible to introduce new powers from the outset," he said in a statement.

"I am calling for stronger powers to allow my office to take swifter action where necessary."

Since the European Commission produced its Privacy and Electronic Communications Directive, the UK government has been obliged to legislate. It has little choice - other than saying who oversees its rules - in deciding the content of its legislation, which makes sending unsolicited emails to an individual illegal unless they request it.

Dai Davis, technology lawyer at law firm Nabarro Nathanson, said that with spammers able to mask the origin of their bulk mail-outs, the Commission would struggle to deal with their technically advanced skills.

"If you talk technical details to the Commission, their eyes just glaze over. What matters is whether they'll get additional resources to hire technical expertise," he added.

The DTI has already admitted that legislation will not stop unwanted emails clogging up networks and said that anti-spam software will continue to play a vital role. Department figures estimate that spam accounted for half of global email traffic in August 2003.

"The fines are part of a wider international attempt to tackle spam," said Stephen Timms, e-commerce minister.

In this regard, the government feels the legislation is useful in helping generate momentum to create global anti-spam legislation.

Any country failing to adopt similar laws will risk becoming a global pariah, as spammers would base their operations there, warned Steve Linford, director of campaign group, Spamhaus.

"It's important to get the message across that unsolicited bulk email is not allowed. The combination of legislation and technology will allow us to beat the problem," he said.

The Information Commission will publish further guidance in November, promised Thomas.