OTTAWA (CP) - Prime Minister Jean Chretien and other career politicians are in danger of succumbing to an elitist, "blinkered mentality" that undermines the public's right to know what government is up to, says Liberal MP John Bryden.

Bryden, a former journalist who has long crusaded for more open government, levelled the charge in a letter last week to Don Boudria, the government House leader in the Commons.

The Liberal backbencher's outburst was sparked by Boudria's refusal to let federal bureaucrats appear before an ad hoc committee of MPs studying reforms to the federal Access to Information Act.

Bryden, a third-term MP who represents a Hamilton-area riding, is chairman of the self-appointed group that includes members from four of the five parties in the Commons.

In his letter, Bryden drew a distinction between those like himself, for whom politics is a "secondary and subsequent career," and those like Boudria, Chretien and Deputy Prime Minister Herb Gray, who have made it their life's work.

"There is no doubt that those who made politics their primary profession, like you, the prime minister, the deputy prime minister and others in cabinet, have been crucial to the fiscal and administrative success of the federal government," wrote Bryden.

"However, there is a peril. Professionalism of any kind tends to engender a blinkered mentality that more and more accepts as valid only the inputs of those within the profession. This can breed orthodoxy, then rigidity, then elitism. After a time, insiders trust only insiders."

Bryden stood by that assessment in an interview Monday, but insisted he didn't mean the comments as a personal attack on Chretien and his cabinet.

"It's not intended as an indictment, not at all," he said.

"It merely, I think, points to the reality of human nature. . .When people are working together over a long period of time, in positions of trust, they begin more and more to listen only to one another."

Bryden intends to raise his concerns about the access law - and the broader issue of backbench participation in government - at a Liberal caucus meeting that starts Wednesday in Edmonton.

Boudria, who was on vacation when Bryden sent his letter last week, refused to comment Monday.

"I don't intend to engage in a debate with a Liberal colleague in public," he said. "The issue is closed and that's the end of it."

A team of bureaucrats, led by the Justice Department and Treasury Board, has been reviewing the 18-year-old Access to Information Act and is due to report in the fall.

That will likely be followed by legislation to update the act, but Boudria would not speculate on when a bill might come before the Commons.

Bryden and other like-minded MPs fear the official review, being conducted in private, is aimed at tightening the access law to make it more difficult for journalists, backbenchers and the general public to obtain information.

The dissidents formed their ad hoc group, which includes nine Liberals, two Canadian Alliance MPs, two from the Bloc Quebecois and one Conservative, to hold their own public hearings.

Bryden had hoped to call officials from several Crown corporations and government departments to testify.

But Boudria informed him about 10 days ago the bureaucrats would not be permitted to appear.

The ostensible reason was that the MPs, since they do not constitute an official Commons committee, cannot offer the usual legal immunity to those who testify.

Boudria also suggested the hearings could impinge on a court case in which Information Commissioner John Reid is challenging the right of Chretien's office to keep his daily appointment schedules private.

Bryden dismissed those concerns and said he was taken by surprise by Boudria's refusal. "It's damaged the work of the committee very significantly."

The MPs will press ahead with hearings scheduled for next week, but they now will be unable to explore some key issues.

Among them are provisions in the current law that allow the government to withhold records of Crown corporations.

Government departments, for their part, can refuse to release anything that is harmful to federal-provincial relations, compromises cabinet secrecy or violates solicitor-client privilege.

Critics have long complained those sections of the law are worded too broadly and are abused by bureaucrats and cabinet ministers eager to hide their activities from public view.