Boris Johnson wrote that the poorest 20% of British society is made up of "chavs", "losers", "burglars", "drug addicts", and "criminals", in a newspaper column unearthed by Business Insider.
The prime minister, who was a Tory MP and editor of the Spectator at the time, wrote in a 2005 Telegraph piece that the "bottom" 20% of British citizens "supplies us with the chavs, the losers, the burglars, the drug addicts and the 70,000 people who are lost in our prisons and learning nothing except how to become more effective criminals".
Labour's David Lammy told Business Insider that the PM's remarks revealed a "disdain for working-class people across the UK".
"Before becoming Prime Minister, Johnson used the privilege of high profile newspaper columns to spew bigoted abuse at Muslim women, black people, single mothers, working-class people and other groups.
"This history makes him unfit to be Prime Minister, especially at a time when our country is divided and desperately needs to come back together again."