Listhaug accused Christian Democrat Party leader Knut Arild Hareide of pandering to extreme elements of society instead of confronting people with extreme opinions during a debate on the NRK P2 radio station.
The Norwegian expression used by Listhaug, “sleike imamer oppover ryggen”, translates approximately to saying Hareide was ‘sucking up to' or ‘prostrating himself before' imams.
The Christian Democrat party gained 5.6 percent of the popular vote in Norway's last general election in 2013 and is a parliamentary ally to the the Conservative-Progress coalition government.
But the socially conservative centrist Christian Democrats are too soft on immigration policy, Listhaug argued.
READ ALSO: Christian Democrats may reject Progress coalition (from 2013)
The phrase used by the Progress Party's immigration minister stoked considerable reaction in Norwegian media, with Hareide himself criticising the tone employed by Listhaug, saying she was more concerned with rhetoric than political reform.
Both Jensen and Listhaug are known for their direct and occasionally strong choice of words.
But Jensen told NRK that she saw the language used by Listhaug as no more than straight talk.
“The Progress Party is the only party that is taking a clear position against people that approve of stoning as a method. When we let things like this go on we are putting our own values at risk,” she said.
“This is quite remarkable. We have worked seriously to fight extremism, but there are clearly no limits to the type of language that can be expected from members of this government,” the Labour Party's Marianne Martinsen told NRK.
After Progress Party deputy leader Per Sandberg previously accused the Christian Democrats of being responsible for terrorist recruitment, Hareide said that the nationalist party's hard tone was detrimental to the centre-right Christian Democrats' parliamentary alliance with the government.
“We have been focused on making political breakthroughs and helping some of the most vulnerable people in our society. The way Progress has treated an ally has been testing,” Hareide said.