OTTAWA -- Canada has no official way of measuring who is and isn't a member of the middle class, Minister of Middle Class Prosperity Mona Fortier said Monday.

Conservative MP Pat Kelly asked Fortier in the House of Commons to provide the number and percentage of individuals who she considers to belong to the middle class.

"The income required to attain a middle-class lifestyle can vary greatly based on Canadians’ specific situation," Fortier replied.

"Canada has no official statistical measure of what constitutes the middle class."

Since her cabinet position as minister of middle class prosperity and associate minister of finance was announced, Fortier has been dogged with questions about she defines the middle class. However, speaking on CTV Power Play shortly after being appointed to cabinet in November, she could not do so.

"There's no unique definition for middle class," she told host Joyce Napier.

"We have to make sure we represent the realities in a rural, remote or even urban setting, regional differences…and respond to the needs of families."

She added that would be learning more about her role in her mandate letter, which has since been released. In it, Fortier is tasked mainly with supporting the Ministry of Finance. However, the few times the words "middle class" are mentioned in the letter, their definition remains unclear.

"You will develop cross-government approaches to ensure that the prosperity and quality of life of the middle class are central to government policy-making," the mandate letter reads.

The letter also tells Fortier to work with finance officials to ensure the department has "the analytical and advisory capabilities that it needs to support and measure the impact of an economic agenda focused on growing the middle class and those people working hard to join it."

Without any official statistical measure for that group, it's unclear how her ministry plans to know whether that group has grown in size or whose quality of life she is measuring.

Still, in her answer on Tuesday, Fortier maintained the actual income that allows Canadians to live a middle-class lifestyle varies based on a number of factors.

As examples, she cited child care expenses and whether Canadians live in large cities as being variables that could impact this "middle-class lifestyle."

Despite having no official statistical measure of the group, Fortier insisted "the government’s focus on middle-class prosperity reflects its priority on policies that grow the economy and benefit a very broad group of Canadians."

According to information from Statistics Canada, the median after-tax income for Canadian households was $59,800 in 2017.