Update 11.16pm A political scientist has said Leo Varadkar's claim that some minimum wage workers are "middle class" is "odd".

The Taoiseach told TV3's Vincent Browne last night that he would include minimum wage workers whose annual salary is under €20,000 in his definition.

Eoin O'Malley is a political scientist in DCU and has said people hope to be defined as 'middle class' but not everyone can be.

"It would seem odd that most people like to be called middle class or identify themselves as middle class but if middle class is going to mean anything you would expect that they're people in other classes as well," he said.

"The idea that somebody who is on the minimum wage would be in the middle clases does kind of stretch the bounds of plausibility somewhat."

Earlier:Taoiseach Leo Varadkar has said that says he considers some people on the minimum wage to be "middle class".

He said that those are the people to whom he refers when he wants to stand up for middle classes.

He made the comment in an interview with TV3's Vincent Browne, who hosts his final show on the station tonight.

Mr Varadkar included the lowest-paid workers when he was asked to define what he considered to be an average "middle class" wage.

"It's between 35 and 40-something thousand, so I would go much broader than that, I would include people who are on the minimum wage, people who work very hard, but would be earning less than that," he said.

When challenged by Vincent Browne on his assertion, he responded: "Over 70% of people describe themselves as middle class and Middle Ireland is even broader again."

Mr Varadkar also gave a clear indication that he is considering a vacant homes tax.

“There are a lot of vacant properties in the country, some of those could be renovated and brought into use, some could be purchased, and I think we need to impose penalties on people who leave houses vacant in areas where there’s a very demand for housing, and those houses should be in use,” he said.