Lord McNally says he fought Tory attempts to undermine the Freedom of Information Act when he was a justice minister in the last parliament

A former Liberal Democrat minister has described the government commission set up to review the Freedom of Information Act as a “rigged jury”.

Giving evidence to the alternative FoI review set up by Labour deputy leader Tom Watson, Lib Dem peer Lord McNally said he had fought previous attempts by the Conservatives and civil servants to undermine the act while serving as minster of justice during the last parliament. He said the timing of the new review suggested the government felt it could now challenge the act.

“What worries me is that under the coalition the Conservatives knew they couldn’t get rid of the FoI [and] within weeks of having a majority they set up this commission, with this membership ... All I can say is somebody has a sense of humour ... Talk about a rigged jury.”

Former home secretary Jack Straw, who has previously said he wants the act to be restricted, and McNally’s fellow Lib Dem peer Lord Carlisle who accused the Guardian of a “criminal act” in publishing the Edward Snowden leaks, are both on the commission. McNally is due to give evidence to the commission, led by former civil servant Lord Burns, on Wednesday.

Lib Dem leader Tim Farron has called for the commission to be scrapped, saying the stance of its members, including Lord Carlisle, is one sided.

McNally said he was surprised MPs weren’t “more indignant” that the government had decided to launch a review of the act less than four years after the justice select committee said it was working well.

“I think post-legislative scrutiny is a good thing,” he said. “[But] the executive assembling chums every so often to look at the issue does not serve the same purpose, however distinguished the chums happen to be.”

McNally, who is a former leader of the Lib Dems in the House of Lords, also voiced concerns that outsourcing of public services was putting more information outside the public domain and said suggestions FoI had a chilling effect on advice give to ministers was a “myth”.

He added: “Where we should be pushing is for better leadership both political and administrative to release of information and to have a real test, [asking] ‘is this really information that can’t be put into the public domain?’

“If there’s not a really good reason, then release it. The government’s digital default of putting out of information is something that should be pursued in parallel with the leadership, political and administrative, to seal off once and for all this culture of secrecy.”