Theresa May has told her cabinet ministers to show “strength and unity” as she attempted to stem a series of leaks and negative briefings.
The PM said “open discussion” was important but that it was vital for it to stay private, her spokesman said.
Number 10 said press briefings were a case of colleagues not taking their responsibilities seriously.
The cabinet meeting came after Mrs May told Tory MPs to end the “backbiting” over disagreements within the party.
At a summer reception for backbench Tory MPs on the House of Commons terrace on Monday, Mrs May told the party “no backbiting, no carping”.
The choice, she said, is “me or Jeremy Corbyn… and nobody wants that”.
Go away over the summer for a “proper break”, she told MPs, and “come back ready for serious business”.
The attempt to instil discipline follows a sustained outbreak of cabinet leaks and leadership gossip.
According to her spokesman, Mrs May told cabinet at its regular Tuesday meeting: “There’s a need to show strength and unity as a country and that starts around the cabinet table.”
Speaking on BBC Breakfast, Home Secretary Amber Rudd said media reports of splits and negative briefings did not reflect her experience in cabinet.
She said Theresa May was “absolutely right” to tell ministers that “what is said in the cabinet should stay in the cabinet”.
The PM’s plea to her party for unity comes after she lost her Commons majority when her snap general election gamble backfired.
Hostile briefings in the press over the weekend appeared to show a growing rift in the cabinet.
On Sunday, Chancellor Philip Hammond suggested colleagues opposed to his approach to Brexit had been briefing against him, following press reports of his cabinet remarks on public sector pay.
During Treasury questions in the Commons, Labour described Mr Hammond as an “enfeebled chancellor”.
“I don’t feel particularly enfeebled,” he replied.