Theresa May urged senior ministers to show "unity" around the Cabinet table as she told them to keep details of their discussions private.
Following a weekend of vicious briefings against Chancellor Philip Hammond, the Prime Minister told Cabinet that some members of the Government had failed to take their responsibilities seriously.
She told the weekly meeting at 10 Downing Street that she had tried to encourage open discussion of policy within Cabinet, but it was vital for the Government that this remained private, her official spokesman told reporters.
The Prime Minister said: "There is a need to show strength and unity as a country and that starts around the Cabinet table."
Mrs May told Cabinet that the briefings and counter-briefings seen over the weekend were "a case of colleagues not taking their responsibilities seriously", said the PM's spokesman.
She told the meeting that as Prime Minister she had introduced a more genuine and collective process of discussion in the development of policy in the belief that this would result in better decision-making, but that privacy was essential for this to work.
The spokesman told reporters that ministers showed "widespread agreement" with the PM's message.
The attempt to instil Cabinet discipline comes after a series of newspaper headlines about Mr Hammond's comments at last week's meeting, culminating in a story quoting an unnamed minister accusing the Chancellor of trying to "f*** up" Brexit.
According to newspaper reports, Mr Hammond was slapped down by the Prime Minister for saying that women could "even" become train drivers - a claim he denied.
A separate report said that he had told colleagues that public sector workers were overpaid compared with those in the private sector.
The Chancellor used a TV appearance on Sunday to accuse Cabinet rivals of trying to undermine his agenda for a "softer" business-friendly Brexit prioritising jobs and the economy.
But The Daily Telegraph quoted one minister as saying: "What's really going on is that the Establishment, the Treasury, is trying to f*** it up. They want to frustrate Brexit."
As Brexit negotiations continued in Brussels, Mrs May used a speech at a Tory drinks party on the House of Commons' terrace on Monday evening to warn against "backbiting and carping" and tell MPs to prepare for "serious business" after Parliament's summer recess.
She warned that infighting could result in Labour and Jeremy Corbyn winning power.
Without a Commons majority, Mrs May will be forced to rely on DUP votes to get Brexit legislation through the Commons and she will require iron discipline from her own party to secure its progress.
Home Secretary Amber Rudd said that ministers had "frank and full discussions" at Cabinet, but said she found reports of infighting "perplexing".
She rejected suggestions that Mrs May had lost her authority as a result of the botched election, telling ITV's Good Morning Britain: "She is respected by the Cabinet, she is our Prime Minister, we do have 54 more seats than Labour and we are getting on with the job in hand."
Asked whether members of the Cabinet were seeking to undermine Mr Hammond because they regard his vision of Brexit as too "soft", Ms Rudd told Sky News: "The Cabinet is united in wanting to make sure that we deliver a Brexit that does protect the economy, that does protect businesses ... Philip Hammond has talked about that and he is absolutely right to do so.
"We want to make sure that we have a soft landing, that we protect jobs and businesses and employers to make sure that the economy of the UK remains robust."
Charles Walker, vice chairman of the 1922 Committee of Tory backbenchers, said Mrs May should sack ministers if they were plotting and briefing.
He told BBC Radio Four's World At One: "If the Prime Minister has to start removing Secretaries of State because they are not focusing on their job, they are focusing on their own personal ambitions, so be it. And she will have the support of the 1922 Committee."
Defence Secretary Sir Michael Fallon called for military discipline from the Cabinet ranks to confront the "dangerous enemy" of Mr Corbyn and defend the Conservative case for sound public finances.
At a summer reception hosted by the Policy Exchange think tank he said: "In this summer of warm prosecco I think we in the Cabinet would also do well to reflect on those military virtues: loyalty, discipline, cohesion, that might better enable us first to concentrate our fire on a dangerous enemy in reach of Downing Street - somebody who would lower our defences, scrap our deterrent, weaken our response to terrorism.
"And second, to better articulate again the moral case for lower taxation, for honest public financing, for wider opportunity, enterprise and ownership - the Conservative case."