OTTAWA - Jean Chretien joined the rarified company of humanitarians Albert Schweitzer, Mother Teresa and Nelson Mandela on Monday as the Queen appointed the former prime minister to the exclusive Order of Merit.

The honour, which is restricted to 24 living members, precious few foreigners and only three other Canadians, vaults a name that for some has long been political mud to an unprecedented level of stature.

Chretien himself said Monday the news left him surprised, honoured and grateful.

"What can I say?" he told The Canadian Press in an interview. "I take it as a great compliment and I accept it with some humility."

"I did my job as best I could and Her Majesty was gracious enough to recognize that."

With the honour, Chretien, 75, joins transplanted American neurosurgeon Wilder Penfield and former prime ministers Mackenzie King and Lester Pearson as the only Canadians named to the order.

At 21 years, King was the longest-serving prime minister in the Commonwealth. Pearson was a Nobel laureate who brought universal health care, the flag and a federal pension plan to Canada. Penfield was the founding director of McGill University's world-renowned Montreal Neurological Institute and the associated Montreal Neurological Hospital.

The Queen's website calls the Order of Merit, founded in 1902 by King Edward VII, a "gift from the sovereign."

It is given to people "of exceptional distinction in the arts, learning, sciences and other areas such as public service."

Robert Finch, chairman of the Monarchist League of Canada, said the announcement is no small potatoes.

"The Order of Merit is an extraordinary honour -- given by the Queen herself and not on ministerial advice," Finch said. "As such, the Queen obviously felt that Mr. Chretien's long, distinguished political career deserved such recognition."

"Mr. Chretien was a key player during the constitutional negotiations in the early '80s and -- love him or hate him -- dedicated much of his life to keeping Canada together."

"I suspect that his role as justice minister in the '80s and as prime minister in the '90s and 2000s allowed Mr. Chretien and Her Majesty to build a solid relationship, one that the Queen felt deserved such a reward."

News of the honour touched off a torrent of public commentary when the story hit the Internet earlier in the day. The tone of the comments appeared split between back-slapping and bewilderment.

"Mr. Chretien devoted 40 years of his life to public service as a proud Canadian," one Toronto Star online reader wrote. (He) made mistakes, of course, but he loved this country and worked to keep Canada together.""

"Your Majesty, you have got to be kidding," wrote another. "We can only imagine what kind of conniving, spin-doctoring and horn-swaggling must have taken place for this 'award."'

Membership in the order, which meets once a year, is marked by an eight-pointed cross finished in red-and-blue enamel. The imperial crown is in the centre and the words "For Merit" are etched in gold surrounded by a laurel wreath.

The formal investiture and presentation is expected to be made at Buckingham Palace this fall.

Born in Shawinigan, Que., the 18th of 19 children, Chretien was Canada's 20th prime minister, leading three majority governments between November 1993 and December 2003.

As minister responsible for constitutional negotiations under then-prime minister Pierre Trudeau, Chretien played a big role in the patriation of the Constitution to Canada in 1982.

He was chief negotiator of the so-called "Kitchen Accord," under which nine provinces agreed to patriation. But his role would cast a shadow over him in his native Quebec, which did not ratify the Constitution.

First elected to Parliament in 1963, he became Liberal leader in 1990. As prime minister, he ended federal deficit financing -- it had reached $42 billion annually by the time he took office -- with a string of surpluses spawned by several years of deep and unpopular spending cuts.

He spent much of his time and effort in office fighting Quebec separatists and the Parti Quebecois. The federal side narrowly defeated a proposal on Quebec sovereignty in a bitterly contested 1995 referendum.

Chretien's government subsequently passed the Clarity Act, requiring a "clear majority" and a "clear question," as well as a constitutional amendment, on a federally defined sovereignty referendum.

Chretien committed Canadian Forces to the war in Afghanistan after the terrorist attacks of Sept. 11, 2001, but later refused to join the U.S. invasion of Iraq without the UN's backing.

His exit from office was marked by his divisive feud with his successor and longtime finance minister Paul Martin, and by the Quebec sponsorship scandal -- over which Martin struck a federal inquiry.

The scandal, involving hundreds of millions of dollars in federal funds to Quebec ad agencies, contributed to the Liberal government's defeat in 2006.

Last year, a federal judge quashed the inquiry's conclusion that Chretien and his top aide bore responsibility for the scandal, ruling that public comments by the commissioner, Justice John Gomery, showed bias and that he prejudged the issues.

Chretien never questioned the Queen's role as head of state in Canada, even as debate raged and an inconclusive referendum was cast over her place in Australia and some polls suggested more than half of Canadians could do without her.

"She is there and it is not a controversy in Canada," he said Monday. "The system is working reasonably well."

"To change it involves constitutional changes. I've been involved in constitutional changes in Canada in the past, and it's not easy."

Liberal Leader Michael Ignatieff offered Chretien his congratulations.

"Mr. Chretien left an unequalled legacy of distinguished public service," Ignatieff said in a statement.

"Jean Chretien is remembered for slaying the deficit, presiding over a period of sustained economic growth, and strengthening Canada's national unity."

Members of the Order of Merit have included the pioneering Crimean War nurse Florence Nightingale, Scouting founder Robert Baden-Powell, poet and playwright T.S. Eliot, former British prime ministers Winston Churchill and Margaret Thatcher, and naturalist and broadcaster David Attenborough.