The government's campaign to get all its services online by 2005 has been labelled a shambles in a report that suggests many existing sites are riddled with serious problems.

The 200-page survey, conducted by the Interactive Bureau and Porter Research (which produces the annual review of the FTSE-100 website), found three-quarters of the 20 'flagship' government websites were in need of immediate attention.

As well as claiming the government's 2005 target was "not realistically achievable", the report branded the prime minister's own website one of the worst. The PM's website was described as "a mess, in need of a thorough overhaul from top to bottom".

The PM's site scored just 40.75 percent. It ranked 19th of 20 sites tested in detail against the government's own guidelines. The report said it scored badly "because its navigation is inept, because of lack of attention to detail, because it is poorly maintained, because coding is of a low standard, because of low-speed dialling and because it allows no provisions for the public to contact either the prime minister or his office".

"Together, these are the 20 sites you would expect to be the standard-bearers of usability and accessibility, good design and technical excellence," said Rodney Tyler, MD of the Interactive Bureau. "By judging these, which should be the best, we can get a fair idea of the overall state of the rest."

The best goverment site of those examined was that of The Department for Education and Skills, achieving 78.5 percent. The worst, the Driver and Vehicle Licensing Agency's site scored just 40 percent.

"We suggest any site that scored 65 percent or less [three-quarters of those in the study] is in need of attention in one area or another," said the report.

Sites that achieved that minimum include The Equal Opportunities Commission (69.5 percent), The Commission for Racial Equality (67 percent) and The Department of Health (65.5 percent).

At the other end of the scale, The Human Rights Unit scored just 44 percent and The Department for Environment, Food and Rural Affairs fared little better at 46.25 percent.

"Perhaps the most widespread and aggravated fault is the presentation of information to the public," said Porter Research analyst Adrian Porter. "All too often masses of material full of unexplained jargon and convoluted incomprehensible English had simply been dumped into official websites with no thought of preparing it for the public or helping them understand it."