Treasury minister James Murray was asked to define "working people" amid speculation that the chancellor could raise some taxes in the Budget next week.
Murray said the government will keep its manifesto promise to "protect working people", but he did not answer directly when asked if that group includes landlords, people who own shares or who sell a business.
"Working people are people who go out to work for their income," he told presenter Nick Robinson on BBC Radio 4's Today programme on Friday morning.
Asked for a fifth time if he would count landlords among that group, Murray said: "I'm not going to get into too many hypotheticals here, Nick."