The government’s decision to publish Ordnance Survey mapping information in a free and re-usable form online is a major victory for democracy campaigners.

The move is likely to result in new and improved online services for citizens, as well as better government transparency, according to experts.

Stephen Timms, who has ministerial responsibility for the wider initiative to put state information online, said at a Downing Street seminar last week: “There are big gains to be made here in accountability and improving the quality of public services.”

Publishing Ordnance Survey data was always a key marker for the government’s commitment to its open data agenda.

Tim Berners-Lee, who is overseeing the initiative, said, “Ordnance Survey data is special. An awful lot of data in a table makes no sense, whereas in a map form it does. It means you can compare things.”

Availability of Ordnance Survey data means developers can create maps that tell people which council is responsible for fixing a particular lamppost, where they can build public footpaths, and the location of their nearest polling station.

Map data can also be cross-referenced with crime, health and education data to help evaluate the effectiveness of public services ­ – a key democratic tool.

For example, a school can be evaluated by the size and relative wealth of its catchment area as well as by its A-level results.

In addition, hospital A&E units could be judged by the amount of crime and traffic incidents in their area rather than by the length of waiting time.

“The first thing is getting the data out there,” said Berners-Lee. “But this move will become more and more about how we join it together.”

Even the act of getting the information published is a major victory for government transparency campaigners.

Since the Power of Information review was published in 2007, persuading public bodies to part with public data has been an uphill struggle. The Ordnance Survey in particular was unwilling to lose a major revenue stream, despite the fact that the information is paid for by taxpayers.

Sir Nigel Shadbolt, professor of Artificial Intelligence, who is helping Berners-Lee with the initiative, said: “This [release of data] is counterintuitive to many public bodies.”

Shadbolt and Berners-Lee hope to introduce measures that will encourage bodies to proactively release data. “Our rallying cry is ‘Not why but why not?’” said Shadbolt.

Developers point out that with open access to public data they can create alternatives to state-funded projects such as Directgov and the TfL web site more cheaply, saving the government millions.

This has already been shown by online services that take raw bus time data and turn it into a local service guide.

On top of this, the government now estimates that making information available for commercial re-use could benefit the economy by up to £1bn.

With all these facts to hand, Gordon Brown must have been asking himself, “Why not indeed?”