Media playback is unsupported on your device Media caption Sir Tim Berners-Lee talks to Mark Easton about the findings

The UK government is the most open and transparent in the world, according to global rankings looking at public access to official data.

But web inventor Sir Tim Berners-Lee, whose organisation compiled the table, says the country has "a long way to go" before it has a fully open government.

Eighty-six countries were assessed for how easy their governments make it for state information to be analysed.

The US and Sweden come second and third in the rankings.

The World Wide Web Foundation, founded by Sir Tim in 2009, accuses many governments of failing to honour their promises to ensure official data is available. It says that in more than 90% of countries surveyed, data that could help beat corruption and improve government services remained locked away from public view.

"There are a lot of countries that have promised to put this basic data out there, really valuable information to cement trust between the government and citizens, but a lot of them haven't followed up," says Sir Tim.

Kenya has fallen 27 places in the overall rankings, from 22nd to 49th position. The foundation says many had hoped the high-profile launch of an open data portal in 2011 would be followed by continuing commitment and a policy framework for open data. "No such framework has come into force," it says.

Developed countries Emerging market countries Developing countries 1. UK 21. Brazil 36. Indonesia (tie) 2. US 22. Mexico 39. India 3. Sweden 33. Hungary (tie) 46. Ghana (tie) 4. New Zealand (tie) 33. Peru (tie) 46. Rwanda (tie) 4. France (tie) 36. Argentina (tie) 49. Kenya

Read the World Wide Web Foundation report

In contrast with the UK, the Republic of Ireland is in 31st position in the rankings, two places lower than last year and the lowest-placed European country. Mali, Haiti and Myanmar, also known as Burma, are at the bottom of the table.

Just dumping data is not the answer, it ticks a box but it doesn't do the job Meg Hillier, Labour MP

"Despite coming top of the rankings, the UK has a long way to go. The release of map data is something where the UK has lagged behind, and you'd think postcodes would be part of the open structure of the UK, but they're not," Sir Tim points out.

"The Post Office holds them as being a proprietary format. So, ironically, just a list of places in the UK is not available openly, for free, on the web."

Central to the UK's place at the top of the ranking is the data.gov.uk website, launched by the Labour government in 2010. The coalition government expanded the government files released on the site, opening up £80bn of government expenditure to public scrutiny.

However, Parliament's Digital Democracy Commission has warned that transparency is not the same as true accountability.

"There's actually a big difference between dumping data that's not easily understandable and actually having open data that clever people can use to help you and me find out the information they want about the subject they want," says Meg Hillier, a Labour MP who sits on the Commission set up by the speaker of the House of Commons.

"One of the things that MPs are trying to get government to do is to make sure data is released in usable formats. Just dumping data is not the answer, it ticks a box but it doesn't do the job."

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Nevertheless, Britain can certainly claim to be far more open and transparent than many other countries. There are now hundreds of Whitehall civil servants whose jobs are linked to the digital revolution - social media managers and digital communications teams responsible for websites, Facebook and Twitter pages.

Many government services, including the rollout of universal credit, are designed to be "digital by default", prompting some to warn about a digital divide opening up between those online and the millions of UK adults who have never been on the internet.

"If you are saving money by doing things digitally, that does free up money and resources to support those who need old-fashioned systems," Meg Hillier points out. "Even in Estonia where everything is on digital they allow people to do anything they want on paper. We must always remember the digital divided and make sure they're not neglected."

For all its problems and challenges, Sir Tim believes the digital revolution should usher in a new age of open and accountable government.

"It has been this massive international collaboration of people that's been really exciting," he says. "People come out of the woodwork doing things because they're just excited about the final world that they're building. Those are the people that I'm proud of."