A hearse carrying the body of Jack Layton arrived Thursday night in Toronto, where the late NDP leader will lie in state at city hall ahead of a funeral expected to draw thousands of mourners.

Toronto was Layton's adopted home, and where he made a name for himself in civic politics. On Saturday, Layton will be honoured with a state funeral at the city's Roy Thomson Hall, where Layton's widow Olivia Chow and Toronto mayor Rob Ford will be in attendance.

Limited seating will be available to the general public, with about 600 seats available to the first people in line at 8 a.m. Canadians are also invited to sign an online book of condolences at www.commemoration.gc.ca.

It is estimated that some 9,000 mourners filed past Layton's casket as he lay in state in the foyer of the House of Commons Wednesday and Thursday. There were so many mourners lined up Wednesday night that some had to be turned away, which prompted officials to extend the hours of the lying-in-state on Thursday.

Speaking to Â鶹´«Ã½ Channel, Layton's friend and communications consultant Barry McLoughlin admitted he was surprised by the "sheer scale" of the turn-out.

"I think it went beyond all measure -- what people witnessed here on Parliament Hill this week and on Saturday it should be even more pronounced."

The popular politician died Monday after a battle with cancer. He was 61 years old.

Mourners arrived early on Thursday, travelling from Ottawa and elsewhere to take their opportunity to say goodbye to Layton.

Among those in the crowd was Maher Arar, the Canadian citizen who was detained and tortured in Syria in 2002 and 2003. Layton was among those who spoke out on his behalf.

Bridget Levesque left her Kingston, Ont., home at 5 a.m., so that she and her young son, Quentin, would be able to pay tribute to Layton on Thursday.

"Quentin earlier this summer wrote a letter to Jack Layton, expressing his admiration for Jack Layton to get the job done right," Levesque told CTV's Canada AM about an hour before the lying-in-state was scheduled to resume on Thursday.

"And he approached his dad and I and asked if we would take him to Ottawa so he could pay his respects, so we've done that today."

Her son said he was captivated by Layton's will to keep going "even when he thought he couldn't do it, but he kept going and going and going."

CTV's Richard Madan said the thousands of mourners expressed a common admiration for the popular politician who led the NDP for more than eight years.

"A lot of people were wearing bright NDP orange, a lot of people had distraught, sad faces, but what was most interesting is there was this sense that Jack Layton connected with these folks," Madan told CTV's Canada AM on Thursday morning.

"A lot of them had never met him before, but they just felt that they connected with his story and Jack Layton was a source of inspiration."

Ottawa resident Athena Amarandos told The Canadian Press on Wednesday that "Jack Layton represented the regular Canadian person and he played an important role in Parliament in bringing government to the ordinary person."

Other mourners shook their heads at the possibilities if Layton had lived on to take part in the next Parliament, which he had intended to return to in September.

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

The NDP's Paul Dewar said Layton made politics accessible to people and he fought to draw attention to their issues and concerns.

"His legacy will be about opening politics up to people and to make sure that people are heard and represented well," Dewar told Â鶹´«Ã½ Channel on Thursday morning.

Layton had led the New Democrats to new heights in the final months of his life, as the party became the Official Opposition for the first time ever after the May election.

But the long-time NDP leader did not get to relish his victory for long. In July, Layton announced he was taking a leave of absence to seek medical treatment for a second battle with cancer. He died four weeks later.

In February 2010, Layton said he had been diagnosed with prostate cancer, for which he received treatment. When he took leave in July, the NDP leader said he was facing a new "non-prostate" cancer, but he did not offer further details on his illness.

Layton was the first Opposition leader to die in office in more than 90 years.

The Quebec-born Layton spent nearly three decades of his life in politics, starting out as a municipal councillor in Toronto and later making the jump to the federal scene.

With files from The Canadian Press