OTTAWA - They came by the thousands, in all ages, shapes and colours to stand in the heavy August humidity and sporadic rain, waiting their turn to bid farewell to Jack Layton.

They filed past the late NDP leader's flag-draped coffin in the foyer of the House of Commons at a rate of about 1,000 per hour, according to a Commons official.

And a long lineup still stretched along the drive in front of the Parliament Buildings as the sun set Wednesday, inching along as each person was checked through security. People at the back faced a wait of two hours or more, but seemed unconcerned.

Athena Amarandos of Ottawa said Layton had the common touch.

"Jack Layton represented the regular Canadian person and he played an important role in Parliament in bringing government to the ordinary person."

The line was the country in microcosm. Blue-rinsed grandmothers rubbed shoulders with teens sporting pink Mohawks. Bearded Sikhs stood beside giggling schoolgirls. There were families with toddlers in strollers, couples young, middle-aged and senior, clutches of friends, and singles lost in thought.

On the buildings around them, flags fluttered at half-mast.

Beside the Centennial Flame, a makeshift memorial grew through the afternoon. There were cards and candles, flowers in every shade of orange, the ubiquitous cans and bottles of Orange Crush.

Hand-lettered signs were propped here and there, including: "We wish we were old enough to vote for you in the last election. Salwa and Sara Khan."

Layton's widow, Olivia Chow, and his children, Mike and Sarah, emerged from Parliament's Centre Block to thank the mourners and were greeted with waves of applause.

Layton was 61 when he died of cancer on Monday. He returned to Parliament for the last time on Wednesday morning, borne on the shoulders of eight scarlet-clad Mounties.

With a piper skirling a lament and the Peace Tower bell tolling, his coffin was carried up a red carpet into the Centre Block, where it will lie in state until it is whisked back to Toronto late Thursday.

Chow, with Layton's children and granddaughter Beatrice, followed the coffin down the stone-walled hallway to the foyer of the Commons. The slow march went in a silence broken only by the clack of riding-boot heels on the marble tiles.

The Mounties laid the coffin on a bier before the door of the Commons, a spot where Layton held numerous scrums with journalists over his years in Ottawa. A black and white photo of Layton was propped on an easel, flanked by Canadian flags.

The family had some private moments in the foyer, then greeted dignitaries, including Gov. Gen. David Johnston, and Laureen Harper, as they came to pay their respects and sign a book of condolence.

Cabinet ministers, MPs, Commons staff, present and former senior officials, and the diplomatic corps paid their visits before the public was allowed in.

Prime Minister Stephen Harper is on his annual Arctic tour, but is scheduled to attend the state funeral in Toronto on Saturday. He spoke of Layton's accomplishments during a news conference, though.

"The thing that immediately comes to mind, of course, is the historic achievement he had with the New Democratic Party," Harper said.

"It's obviously a tragedy and unfortunate that he's not able to survive to really enjoy that achievement the way he should have."

The NDP and its CCF predecessor strove for decades to attain the breakthrough that Layton made when he won the title of leader of the Opposition.

Chow was stoic as she greeted people, but cracked a bit when former NDP leader Ed Broadbent swept her into a hug. At one point, Chow even comforted a weeping MP

Broadbent, Layton's predecessor, said Layton left a solid legacy.

"He's restored civility to public life. He's made Canadians, once again, believe in politicians. He transcends -- at least for the moment -- all partisan considerations.

"He had a remarkable life as a politician. He was proud to be a politician. He preached, if I can put it that way, the best of values."

Robert James Drummond of Ottawa was in the crowd waiting to pay his respects.

"I was terribly broken up over his death," Drummond said. "I have no doubt in my mind whatsoever that he would have been Canada's next prime minister."

The hearse left Toronto in the pre-dawn hours and arrived in the capital at mid-morning behind a police escort which closed the on-ramps and gave the cortege a clear road.

The coffin will return to Toronto to lie in repose at City Hall before the state funeral at Roy Thomson Hall on Saturday afternoon.

Officials announced that the CN Tower would sport orange lights on Saturday night in Layton's honour.

The formal state funeral, normally accorded only to current and former prime ministers and governors general and current cabinet ministers, was offered by the prime minister out of respect for Layton's stature.

Even before he is laid to rest, speculation is swirling about who will replace him at the helm of the NDP.

One of Layton's closest advisers is emerging as a surprise front-runner. Insiders say party president Brian Topp is receiving a lot of encouragement from influential quarters to join the impending race to succeed Layton.

Topp is one of the key architects of Layton's success and was among the last of Layton's tight-knit inner circle to speak with him before his death.

Montreal MP Thomas Mulcair, Layton's deputy leader, is widely considered the only other prospective candidate to have a serious shot at taking Layton's place.

Layton broached the leadership issue in a death-bed letter to Canadians, released just hours after his death. Topp, along with Chow and Layton's chief of staff, Anne McGrath, helped Layton craft the letter Saturday, just over a day before the leader passed away.

In it, Layton urged the party to choose a replacement as soon as possible in the new year, giving his successor almost four years before the next election to put his or her stamp on the party.

The party's federal council is expected to meet the first week of September to set the leadership process in motion. A leadership vote is likely in mid-January.