Three-year-old Lola was told her outfit for preschool was "inappropriate."

When three-year-old Lola Stonehouse came to preschool wearing a sundress on a particularly hot day, her parents thought nothing of it.

But that day, Jamie and Sadie Stonehouse were told via text that if Lola were to wear that dress again, she would need to wear a T-shirt underneath.

Lola attends The Little Years Nursery School in Winnipeg, Canada, and staff reportedly thought her dress was “inappropriate.”

According to Lola’s father, who spoke to Canadian TV news network CTV, the school says girls must have straps that are at least two inches wide.

Lola's mum is distressed about how to tell her young daughter that she can't wear her sundress to school.

“She’s not going to understand," she told CTV.

"She’s going to think that maybe she did something wrong, when she very much didn’t.

“So now she’s going to be questioning her own body. And that’s such a young age to even be thinking of something like that.”

While the director of The Little Years Nursery School has refused to comment on the situation, a spokesperson for the wider schools devision clarified to CTV that they don't have a dress code policy, and instead delegate that decision to "school leaders".

"School leaders to use discretion and encourage best practices in a respectful way," they said.

For now, both Jamie and Saidie have stated that they will no longer send Lola to preschool in her sundress - even if it's a decision they don't agree with, and are hoping that it's a rule the school will review.

“It’s a child," says father Jamie.

"Innocence is innocence and we’re the only ones who can give it to them."

Should toddlers be subject to dress codes? Let us know in the comments below.