A well-known private school in Ottawa is facing several lawsuits from upset parents and former student teachers, and some say its future is uncertain due to mounting debts of more than $1 million.

Sylvia Robbins withdrew her son from the school because she was concerned about a high turnover rate among teachers. (CBC)

The Canadian Montessori Academy has been operating in Ottawa since 1980. It's located in a former Catholic elementary school at 70 Fieldrow St. in Nepean.

The school is owned and run by the de Mel family, and its principal is Sherie de Mel.

Sylvia Robbins said she enrolled her then nine-month-old son at the academy in 2010. A year later, she became concerned by the high turnover of teachers.

Former teacher quit due to stress

"When none of our old teachers had returned in both infant and toddler classes, alarm bells were going off in my head, like ding, ding," she said. "Like, the whole staff just doesn't quit."

Stephanie Cummings started working at the school in August 2011 as the head teacher in the toddler program.

She told CBC News working at the school was like watching a revolving door, and that sometimes there were too few staff looking after too many children.

"I was having nightmares," Cummings said. "I couldn't sleep at night. I was thinking about kids running out on the street."

'I just could not take it anymore,' former teacher says

She said her concerns were ignored by the de Mel family. After less than a year on the job, Cummings said the stress was making her sick and she quit in May this year.

Stephanie Cummings, former head teacher of the toddler program at Canadian Montessori Academy, said she quit in May due to stress. (CBC)

"I just could not take it anymore," she said. "I was afraid something very wrong was going to happen to one of the toddlers in my care."

Robbins and her husband pulled their son out of the academy in May. They're suing the school to recover $25,000 in tuition, citing unsafe conditions at the school and a lack of qualified Montessori teachers.

"It just makes me sick to my stomach to think he was there," Robbins said.

Family, lawyer, have not commented

Earlier this week, a school receptionist said the de Mels are in Florida. So far, neither the family nor their lawyer have commented.

But in a statement of defence filed just this week, the de Mels deny all of Robbins' allegations and said they plan to counter sue.

The school is embroiled in many other legal battles.

Two other recent lawsuits filed by parents accuse the de Mels of deliberately hiding the fact they had been negotiating to sell the property to Minto.

The de Mels have argued that they acted openly and honestly.

Debts mounting to more than $1 million

Cummings said the potential sale of the property worsened a rift between her and her employers.

"So when these parents started asking questions and I started asking questions, then they stared telling us (teachers) we could not talk to the parents anymore."

The sale to Minto has fallen through, but the property could soon be subject to a forced sale by the city which, according to a court document, claims it's owed close to $480,000 in back taxes.

The document indicates the sale could take place as soon as July 25.

Province, federal government also demanding money

Other levels of government are demanding money from the school.

The Canada Revenue Agency has placed a series of liens on the property for thousands in unpaid taxes. One registered in October 2007 says it's owed more than $199,000. Another registered in April 2010 says it's owed more than $230,000. Three other liens were filed by the CRA.

In June, the province of Ontario served the school with a writ under the Corporation Tax Act claiming it's owed more than $22,000.

In a statement of claim, the Business Development Bank of Canada claims the school defaulted on a loan and owes more than $700,000.

Sherie de Mel is the principal at Canadian Montessori Academy.

The federal agency said principal Sherie de Mel is personally liable for half this amount.

The de Mels are fighting the case. A date to go to mediation has not yet been set.

None of the claims against the school have been proven in court.

But Robbins doubts the school will be open much longer.

"Personally I think September is going to come around and the doors are going to be shut with a note on the door saying we are out of business," she said.

The de Mels, meanwhile, continue to express confidence for the school's future.

Sherie de Mel recently sent a letter to parents encouraging them to register for the 2012-13 school year.