OTTAWA -- Well-founded complaints about Transport Canada's handling of access-to-information requests on the Lac-Megantic train disaster contributed to a 30 per cent increase in grievances about federal agencies last year.

In her annual report, Information Commissioner Suzanne Legault said she continues to have serious concerns about the access system -- and the resulting harm to Canadians' right to know.

The Access to Information Act allows people who pay $5 to request a variety of records from federal agencies -- from correspondence and briefing notes to expense reports and audits.

The government is supposed to respond within 30 days, or provide good reasons why a delay is necessary.

Dissatisfied requesters can complain to Legault's office about a delay, the refusal to release information, additional fees or other matters.

The rise in complaints -- to 2,081 in 2013-14 from 1,465 the previous year -- is explained, to some extent, by an overall increase in the number of requests to federal agencies, said Legault's report, tabled in Parliament on Thursday.

However, she stressed that only some organizations successfully absorbed this growth, while others had difficulty meeting their basic obligations under the law.

"This decline in performance must be promptly addressed," Legault said in her report. "Canadians should be concerned and speak out whenever their quasi-constitutional right of access is in jeopardy."

Transport Canada received more than 200 access requests in the nine months after a freight train crashed into the town of Lac-Megantic, Que., last July, exploding in a cascading series of fireballs that killed dozens of residents.

The department took time extensions on requests ranging from 300 to 365 days beyond the standard 30-day limit, citing a large volume of records to sift through or the need to consult other agencies. That prompted several complaints from requesters.

"During the investigations of seven complaints completed in 2013--2014, it became clear that the extensions Transport Canada had taken were not valid," Legault's report said.

"In some cases, the page volume was insufficient to justify extensions to search for and through records. In another, the extension was for consultations with other institutions that Transport Canada never undertook."

The information commissioner asked Transport Canada to provide a firm date for responding to each of the seven requests, which the agency did, the report said.

"In all cases, the institution responded to each request on or before the deadline, resulting in requesters' receiving a response significantly earlier than Transport Canada had initially proposed."

The commissioner's office faces an increasing workload with a shrinking budget.

Legault called on senior officials at agencies "to step up their leadership" on access to information in their organizations and across government.

Both the ministers responsible for federal agencies and the deputies who run them are responsible for meeting these obligations, she said in an interview. "But the minister sets the tone at the leadership level."

Stephen Harper's Conservatives broke their 2006 election campaign promise to thoroughly revamp the Access to Information Act.

Legault renewed her call to modernize the law -- which has barely changed since it took effect in 1983 -- to ensure government transparency and accountability. "You cannot have open government with a 30-year-old piece of freedom-of-information legislation."

Administrative fixes to the system, which are bearing some fruit, can only do so much, she said.

In the House of Commons, New Democrat MP Pat Martin said Legault's report "confirms that the black shroud of secrecy is destined to become the single most defining hallmark of the Conservative government."

Martin pressed the government on why it abandoned plans to reform the law.

Treasury Board President Tony Clement did not address the point, instead citing the growing volume of requests that federal agencies have answered since the Tories took power.

"That is our record on access to information and we are darn proud of it."