Jess Phillips has attacked leadership hopeful Boris Johnson in a series of tweets, branding him a "hollow icon".
The Labour MP accused the politician of having "no guts", as Tory MPs began voting on who they wanted to become their next party leader.
“I do not fear him as an opponent to be honest I pity him, because he doesn't passionately believe in anything," she wrote.
"His authenticity rubs off with even the slightest brushing. He's a hollow icon who cannot even defend his words.”
In response to a Twitter user defending Mr Johnson as a “man of the people”, Ms Phillips said he “would not live down your street”.
“He would not let his children go to school with yours, he does not hang out where you hang out and he would not be your friend,” she added.
Mr Johnson secured the highest number of votes in today's ballot, with 114 Tory backers.
Andrea Leadsom, Esther McVey and Mark Harper were knocked out of the race, bringing the total of leadership contenders down to seven.
Defending her Twitter tirade directed at the former foreign secretary, Ms Phillips said she had friends who were "frightened for their country".
“If you think I'm being harsh on BJ [Boris Johnson] you don't have any Muslim women friends or family because mine have all been messaging me sadly this morning frightened for their country,” she wrote.
Former Green Party leader Caroline Lucas has called Mr Johnson a "racist" and "serial liar" in her response to Mr Johnson's overwhelming victory.
On Twitter she wrote: "So a serial liar, racist and one of most incompetent ministers ever leads the poll in the Tory leadership contest. Conservative MPs should hang their heads in shame."