Attawapiskat Chief Theresa Spence will attend tonight's ceremonial meeting with Gov. Gen. David Johnston, after she boycotted an earlier meeting between Prime Minister Stephen Harper and other chiefs.

Spence’s last-minute decision comes as Harper wrapped up the controversial meeting with aboriginal leaders. She refused to attend that meeting because she insisted that Johnston and Harper be in the same room together while addressing the chiefs.

Meanwhile, thousands of First Nation protesters descended on Parliament Hill.

A crowd that police estimated at 3,000 gathered outside the Prime Minister’s Office in opposition of the working session between federal officials and Assembly of First Nations leaders.

The protest was peaceful, said CTV’s Ottawa Bureau Chief Robert Fife, reporting from outside the Langevin Block building where the meeting was taking place, with demonstrators chanting, drumming and dancing in the area.

“They’re being very respectful,” Fife said. “But they clearly do not want this meeting to go ahead.”

Initially, the Prime Minister said Thursday he’d only attend part of the scheduled five-hour meeting: the first half-hour and then again at the end, to receive a summary of the talks.

But his press secretary Carl Vallee announced Friday afternoon that Harper will attend the entire meeting, which wrapped up after 5:30 p.m. ET.

Throughout the week, First Nations chiefs have been deeply divided over the meeting, with top chiefs from Ontario, Alberta, Saskatchewan, Manitoba and the Northwest Territories vowing to stand with Spence in her refusal to meet with Harper unless he’s joined by Gov.-Gen David Johnston.

Johnston has ignored those calls, committing only to hosting a “ceremonial meeting” at his official residence, Rideau Hall, on Friday evening.

Spence spoke to reporters Friday morning on Ottawa’s Victoria Island, where she has spent the last month on a liquids-only diet in hopes of securing a face-to-face meeting with both Harper and Johnston.

It was her first appearance since the release of a federal audit on Monday showed a significant lack of documentation for $104 million in federal transfers made to the northern Ontario reserve from 2005 to 2011.

Shortly into the address, hecklers interrupted Spence, asking what was made of the federal funding. However, Spence refused to take questions.

“We shared our lands all these years and we never got anything from it. All the benefits are going to Canadian citizens,” said Spence.

“For the government, he makes false statements about funding,” she continued. “He doesn’t give details on where (the money) goes. Most of the funding that we have, it goes back to your to taxpayers, it goes out of the reserve.”

Following the brief media address, a spokesperson said Spence will continue the liquids-only diet for the time being.

The spokesperson also said unless Harper and Johnston meet with aboriginal leaders together in the same room, Spence would not partake in the meeting.

Spence insists Johnston’s presence is vital since the talks will centre on treaty rights that were first established by the Royal Proclamation of 1793.

The highly-publicized hunger strike has drawn further attention to the broader Idle No More movement, which protests the federal government’s omnibus budget legislation. Protesters say the Conservative budget bill threatens First Nations treaty rights as set out in the Constitution.

While several chiefs sided with Spence and boycotted the meeting, Assembly of First Nations National Chief Shawn Atleo encouraged First Nations leaders to present a united front to the federal government.

During a news conference Thursday afternoon, Atleo called the meeting the beginning of a “transformative change” between Canada’s First Nations and the federal government.

“This is the fork in the road,” Atleo said. “This is the moment of reckoning and the tipping point that for so long we’ve said was coming.”

The working session aims to set First Nations priorities with the federal government moving forward. A separate ceremonial meeting with Johnston is planned for Friday evening.

Atleo pleaded for unity Thursday night, admitting that his membership was divided.

"This is not a perfect organization and I am not a perfect person. I accept a share of responsibility and I have responded to criticisms from last January," Atleo told a room of chiefs and delegates in Ottawa. "We need to continue to stand united -- chiefs, delegates....If we are to be divided at a moment like this, the governments will see that."

CTV’s Chief Political Correspondent Craig Oliver said divided group leaves Atleo in a difficult position with no clear mandate on which to launch negotiations with the Prime Minister.

“Shawn Atleo was an elected chief, but not by any means by all the chiefs. They have their own divisions,” Oliver said. “The real story here is that there are 630 First Nations, all of them regard themselves as sovereign…they have a hard time saying yes as a group, and that alliance at this point has collapsed entirely.”