Chief Rudy Turtle of the Grassy Narrows First Nation will run for the NDP in Kenora, Ont. this fall.

The announcement comes amid frustrations within Turtle's community over delays in the construction of a promised mercury poisoning treatment centre, which then-Indigenous Services Minister Jane Philpott first pledged to build in late 2017.

The First Nation community has been ravaged by the health impacts of mercury being dumped in its local river in the '60s and '70s, which range from impaired cognitive functions and issues with speech, vision and hearing. With prolonged exposure, the damage can become irreversible – rendering access to treatment all the more urgent.

Turtle said he’s running because he believes Prime Minister Justin Trudeau has "let Indigenous people and nations down," including with respect to the promised treatment facility.

"What tipped the balance is the inaction and the [continuation] to stall with our mercury treatment home, and it's been a very difficult situation. They've done everything to stall this process and to make it go slow each and every day," Turtle said in a press conference on Monday.

"I'm getting worried that it might not even happen."

In a press release from the NDP, Turtle widened his criticism to the government’s treatment of Indigenous people more broadly.

"Justin Trudeau promised us that he'd be different, but what we got was a prime minister that says the right thing in public, and does another behind closed doors," Turtle said.

"When Indigenous communities want to work with Trudeau — on issues from clean water to community safety — we get a condescending Prime Minister that's willing to pose at ceremonies, but not willing to take action to make people's lives better. Like millions of others, I'm tired of being let down."

Turtle said he joined the NDP because he thinks the party "walks the walk of reconciliation."

The riding of Kenora is currently held by Liberal MP Bob Nault. He secured the seat in 2015 after beating the NDP candidate, Howard Hampton, by just 498 votes. There were over 30,000 ballots cast in the riding during that election.

NDP Leader Jagmeet Singh said he's "proud" to welcome Turtle to the NDP team.

"We've got a strong history of support in Kenora. We've held the riding in the past. This is a very important riding for us," said Singh.

"Chief Turtle has led the fight for the people of Grassy Narrows in the battle for recognition of the mercury contamination...Mr. Trudeau had a lot of great announcements, a lot of great words but failed on actions and broke many promises, leaving many people disappointed – and Grassy Narrows is the epitome of that broken promise."

The federal government has blamed jurisdictional issues for the delay in the construction of the mercury poisoning treatment centre. In an interview with CTV's Power Play in late April, Indigenous Services Minister Seamus O'Regan said the feds need to work with Ontario Premier Doug Ford's government to provide the "highly specialized medicines" required in the treatment of mercury contamination.

"We haven't been as engaged with this government," O'Regan said. "We need to be. We need them to be at the table."

In a statement emailed to CTV News on Monday, a spokesperson from O'Regan's office reiterated the government's commitment to get the facility built – although it did not provide a timeline of when that would take place.

"A technical group is meeting regularly to move forward the plans for the facility—the most recent meeting took place last Wednesday and was productive. The technical group is scheduled to meet again this week. At the same time, work is underway between all partners – the province, our government, and the community—to ensure the necessary health services are in place for the facility itself," the statement read.

"We will continue discussions on this with Chief and Council until we reach a consensus. We will get this facility built."

Despite the ongoing negotiations with the government, Turtle plans to stay on as chief.

"I will step down if, or when, I win," he said.

Public opinion on the government’s commitment will be put to the test when voters head to the polls for the federal election, which will take place on or before Oct. 21.