Boris Johnson has been slapped down by a senior Cabinet colleague after saying a Libyan city could become the next Dubai once it had cleared the dead bodies away.
The British Foreign Secretary is facing calls for his sacking over the comments on the fringes of the Conservative conference.
Damian Green, the UK's de facto deputy prime minister, rebuked Mr Johnson and said his comments were "unacceptable".
He told Sky News: "Everyone, including Boris, needs to be careful in their use of language."
Boris Johnson tells a fringe meeting that a Libyan city will become "the next Dubai" if they "clear the dead bodies away" pic.twitter.com/jgyy4lCvRw— SkyNews (@SkyNews) October 3, 2017
As the First Secretary of State toured the television and radio studios to talk about British Prime Minister Theresa May's conference speech, he faced repeated questions about Mr Johnson's remarks.
He told BBC 5 Live Breakfast: "Let me be clear it was not an acceptable use of ... it was not a sensitive use of language."
Tory former minister Anna Soubry said Mr Johnson is "embarrassing & PM should sack him".
Heidi Allen, a Tory MP who represents South Cambridgeshire, tweeted: "100% unacceptable from anyone, let alone foreign sec. Boris must be sacked for this. He does not represent my party."
Tory MP Sarah Wollaston told BBC Radio 4's Today: "Well I think these remarks were crass, poorly judged, grossly insensitive and this is from the person who is representing us on the world stage, I think this is really disappointing."
She added: "Of course he should unequivocally apologise, not sort of try to justify those kinds of remarks and the way in which it was said.
"I think he should consider his position."
Shadow foreign secretary Emily Thornberry said the remarks were "unbelievably crass, callous and cruel".
Mr Johnson was made to "move on" after he told Tory activists that investors want to transform the coastal city of Sirte, where dictator Muammar Gaddafi was killed during the 2011 civil war, into a new version of the emirate.
But when he said their only obstacle is to "clear the dead bodies away", the host of the conference fringe event stepped in.
As Mr Johnson continued to speak, Baroness Stroud, a former special adviser to ex-Cabinet minister Iain Duncan Smith, said: "Next question."
The Legatum Institute chief executive added: "The dead bodies was the move-on moment."
Mr Johnson had been asked about his recent visit to the country, which has been wracked by violence since the fall of its former leader.
The British Foreign Secretary said: "I look at Libya, it's an incredible country.
"Bone white sands, beautiful sea, Caesar's Palace, obviously, you know, the real one.
"Incredible place. It's got a real potential and brilliant young people who want to do all sorts of tech.
"There's a group of UK business people, actually, some wonderful guys who want to invest in Sirte on the coast, near where Gaddafi was captured and executed, as some of you may have seen.
"They have got a brilliant vision to turn Sirte into the next Dubai."
He added: "The only thing they have got to do is clear the dead bodies away," before laughing.
Ms Thornberry said: "It is less than a year since Sirte was finally captured from Daesh by the Libyan Government of National Accord, a battle in which hundreds of government soldiers were killed and thousands of civilians were caught in the crossfire, the second time in five years that the city had seen massive loss of life as a result of the Libyan civil war.
"For Boris Johnson to treat those deaths as a joke, a mere inconvenience before UK business people can turn the city into a beach resort, is unbelievably crass, callous and cruel.
"If these words came from the business people themselves, it would be considered offensive enough, but for them to come from the Foreign Secretary is simply a disgrace.
"There comes a time when the buffoonery needs to stop, because if Boris Johnson thinks the bodies of those brave government soldiers and innocent civilians killed in Sirte are a suitable subject for throwaway humour, he does not belong in the office of Foreign Secretary."
Mr Johnson defended his comments, saying: "Shame people with no knowledge or understanding of Libya want to play politics with the appallingly dangerous reality in Sirte.
"The reality there is that the clearing of corpses of Daesh fighters has been made much more difficult by IEDs (improvised explosive devices) and booby traps."