Freedom of information requests are being delayed for months by government departments and other public bodies, says a committee of MPs.
The act grants access to information held by 100,000 public bodies
The Commons constitutional affairs Committee says openness laws introduced 18 months ago are working.
But some organisations are breaking the spirit of the laws by tying up requests in red tape, say the MPs.
They also criticise the watchdog who oversees the system for not doing enough to resolve complaints quickly.
Information Commissioner Richard Thomas is still working to tackle the backlog of complaints about information requests being blocked.
He has asked the government for more funding. Ministers have offered more money but not as much as Mr Thomas wanted.
Since January 2005, the public has been able to force more than 100,000 organisations to release information, although some documents are exempt.
In a report on how the laws have worked, the MPs say they have brought about the release of significant new information.
Public authorities are making efforts to meet the demands of the laws, they say, but they point to delays.
Some organisations are "indefinitely" delaying releasing information for months while they assess the public interest arguments and conduct internal reviews, says the report.
And there are many cases where organisations are not meeting their legal duty to respond to requests within 20 days.
The MPs point to three cases where the Home Office "exceeded the 20 day deadline by several months".
And Friends of the Earth says the deadline was not met in 81 of the 108 requests it made during 2005.
Government statistics show responses to about 10% of all requests made to central government were answered late.
Breaking the backlog
The MPs are also worried about the time it takes the watchdog to adjudicate on complaints.
"Our overall impression is that the complaints resolution process provided by the information commissioner during 2005 was unsatisfactory," they say.
Some public bodies and people making requests have waited months for the commissioner to start investigating their complaints, says the report.
But the committee praises Mr Thomas' efforts to learn from the first year's "challenging workload" to investigate complaints more efficiently.
It says the watchdog should be directly responsible to and funded by Parliament, rather than the government.
The committee also accuses ministers of being complacent about preserving digital records on computer systems.
The National Archives has warned that computer records can disappear a few years after being created unless they are managed properly.
The MPs say Constitutional Affairs Minister Baroness Ashton has failed to recognise this is a serious threat.
"Plans are needed to handle the rapid and significant changes in technology and the inevitable degradation of storage media," says the report.
Maurice Frankel, the director of the Campaign for the Freedom of Information, said: "People who have been refused information have had to wait a year or sometimes even more to get a final decision as to whether they are entitled to that information."
The information commissioner's office said its performance had improved since 2005.
"We are now closing more cases than we receive each month and issuing a steady stream of formal decisions on issues of substance," said a spokeswoman.
"Although we received part of the additional funding we requested from the government, we note the committee remains unconvinced that we have adequate resources."
The spokeswoman said the commissioner was pleased the MPs backed his decision to take a "firmer approach" to enforcing the laws.
The Department for Constitutional Affairs says it is considering the MPs' report.
But its latest quarterly bulletin on freedom of information says "departments' performances continues to improve or be maintained at an acceptable level".
It suggests there is now greater openness, with 68% of "resolvable requests" resulting fully disclosed and only 14% withheld in full.