Rival militias fought with each other for control, and battled with extremists linked to the Islamic State group.
Mr. Johnson was participating in a panel discussion in Manchester, England, on Tuesday when he began to praise Libya for its "bone-white sands, lovely sea" and fine architecture, according to the BBC.
"For Boris Johnsonon to treat those deaths as a joke - a mere inconvenience before United Kingdom business people can turn the city into a beach resort - is unbelievably crass, callous and cruel", said Thornberry, also a deputy in the British parliament.
He then said the only obstacle to this was "to clear the dead bodies away" - this response prompted Baroness Stroud to move the conservation on. "He does not represent my party", Allen tweeted.
Fellow MP Anna Soubry tweeted that Mr Johnson "is embarrassing and PM should sack him".
The Foreign Secretary blamed ISIS for making it more hard to retrieve corpses and insisted his controversial remark to Tory activists was not a joke.
He said: 'Shame people with no knowledge or understanding of Libya want to play politics with the appallingly risky reality in Sirte.
The country has since descended into an ongoing civil war, with thousands of casualties mounting.
More Tory MPs have joined calls for Boris Johnson to consider his position in the wake of his controversial comments about the need to "clear up the bodies" in northern Libya.
"For Boris Johnson to treat those deaths as a joke - a mere inconvenience before United Kingdom business people can turn the city into a beach resort - is unbelievably crass, callous and cruel".
"If Boris Johnson believes that bodies of courageous government soldiers and innocent civilians who were killed in Sirte are appropriate for a material of humor, foreign ministry does not belong to its mandate", Thornberry said. "May needs to get her house in order and sack him", Swinson said.
But Mr Johnson hit back, tweeting: "Shame people with no knowledge or understanding of Libya want to play politics with the appallingly risky reality in Sirte".
Boris Johnson΄s career has been marked by a series of blunders, with the politician sticking to his flamboyant style even after taking over as Foreign Secretary previous year.
Mr Johnson's made the off colour remark at the end of a fringe meeting at the Tory conference in Manchester last night while answering questions about Libya's future prospects.
"She won more votes than any party leader and took this party to its highest share of the vote in any election in the last 25 years and the whole country owes her a debt for her steadfastness in taking Britain forward as she will to a great Brexit deal, based on that Florence speech on whose every syllable, I can tell you the whole Cabinet is united".