Nancy Pelosi’s escalating feud with Alexandria Ocasio-Cortez and a handful of fellow female Democratic progressives known as “the squad” shows no sign of abating after the House speaker criticised intra-party attacks on social media.

“You got a complaint? You come and talk to me about it. But do not tweet about our members and expect us to think that that is just okay,” Ms Pelosi warned during a closed-door meeting of Democrats on Wednesday.

Although Ms Pelosi mentioned no names, many interpreted her comments as targeted at Ms Ocasio-Cortez, commonly known as AOC, along with fellow congresswomen Ilhan Omar, Rashida Tlaib and Ayanna Pressley.

All have been unafraid to criticise centrist Democrats who they believe are falling short of pushing for progressive values.

Some Democrats in the room told Politico they believed the comments were directed against congressman Mark Pocan, who called members that supported the Senate version of an emergency humanitarian package members of a “Child Abuse Caucus”.

Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Show all 15 1 /15 Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez greets fellow lawmakers ahead of the State of the Union address Getty Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez participates in an event with Democratic members of Congress EPA Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures The Democrat senator speaks during a news conference at the U.S. Capitol January 30, 2019 Getty Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez and fellow Democrat Rashida Tlaib AP Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez at the Senate chamber to watch two votes on January 24, 2019 Getty Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez arrives with Chellie Pingree at a House Democratic Caucus meeting Getty Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Ocasio-Cortez during Donald Trump's State of the Union address Reuters Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures New York State Assembly member Catalina Cruz with Ocasio-Cortez AFP/Getty Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Nydia Velazquez talks with Alexandria Ocasio-Cortez Reuters Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Ocasio-Cortez casts her vote for Nancy Pelosi as Speaker of the House EPA Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez poses with a campaign worker during a whistle stop in the Queens borough of New York Reuters Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Ocasio-Cortez outside the US Capitol AFP/Getty Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Ocasio-Cortez after casting her ballot in the 2018 midterm general election at a polling site in New York EPA Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Alexandria Ocasio-Cortez looks on during a march organised by the Women's March Alliance in Manhattan Reuters Alexandria Ocasio-Cortez - the Democratic congresswoman in pictures Ocasio Cortez looks on at the Capitol in Washington, DC, on January 16, 2019 AFP/Getty

But Ms Pelosi, who denied the comments were about any individuals, has repeatedly dismissed the four congresswomen’s influence and their left-wing proposals, including over the weekend when she mocked their opposition to the emergency border bill.

AOC later hit back by criticising Ms Pelosi as "outright disrespectful".

“When these comments first started, I kind of thought that she was keeping the progressive flank at more of an arm’s distance in order to protect more moderate members, which I understood,” she told The Washington Post on Wednesday.

“But the persistent singling out ... it got to a point where it was just outright disrespectful ... the explicit singling out of newly elected women of colour.”

Ms Pressley called Ms Pelosi's comments "demoralising" and said they could send the wrong signal "to people I speak to and for".

The lengthy closed door session on Wednesday underscored the broader divisions between Ms Pelosi's centrist and liberal members that are testing party unity and reshaping Democrats ahead of the 2020 election.

"Without that unity, we are playing completely into the hands of the other people," Ms Pelosi said, according to a person who was in the meeting room but not authorised to talk publicly about the internal discussion.

"We're a family and we have our moments," Ms Pelosi told colleagues.

Then came another warning to those who may want to publicly attack the members who make up her majority: "Think twice," she said. "Actually, don't think twice. Think once."

AOC arrived late to the session and did not speak, according to a second person who attended the session.

But she had already delivered her own lengthy defence of her tactics in an interview with The New Yorker, in which she decried the consolidation of power in Congress and urged her party to be bold about their priorities in ways that voters will hear.

"I think we became the party of hemming and hawing and trying to be all things to everybody," she said.

Donald Trump's deportation plan is 'scaring the children of America', says Nancy Pelosi

"We're too often afraid of our own values and sticking up for them ... And so one of the things that I wanted to do was to hold a strong line.

“I don't think we should be afraid of being the party of FDR. I don't think we should be afraid of being the party of working people."

The tension between the most powerful Democrat in the country and one of the party's newest, most liberal members embodies a debate over how best, in style and substance, to defeat Donald Trump and win the next election.

Six months into the House Democrats new majority, the flare-up is now challenging the House agenda and rippling across the campaign trail.

Hakeem Jeffries, the caucus chairman, downplayed the rift after the morning meeting. "It's all puppies and rainbows," he told reporters.

One test will come this week on a must-pass defence bill that the White House has threatened to veto. Democrats will be forced to unify to pass the bill on their own, without GOP support.

Another test will be former special counsel Robert Mueller's testimony next week in a high-stakes hearing amid rising calls for Trump's impeachment.

Ms Pelosi, who has dialled down efforts to start impeachment proceedings in favour of a more methodical approach to confronting the administration, drew applause in Wednesday's private session.

Other lawmakers, some first-term members, including Virginia's Abigail Spanberger, who helped flip Republican seats to the Democratic column in 2018, also made the case for playing on the same team and keeping the internal drama private, another person in the room said.

Yet, about the same time, Justice Democrats, a group aligned with AOC, was sending out notice that it was backing primary challengers to several congressional Democrats ahead of next year's elections. They are targeting incumbents in Texas, Missouri and a House committee chairman in New York.

"We want to focus on building this new generation of leadership that actually champions solutions that match the scale, scope and urgency of the crisis we're facing," said Alexandra Rojas, the group's executive director.

It is "hypocritical", she said, for Ms Pelosi to make a plea for unity while catering to the views of centrist Democrats over progressives, particularly while refusing to bring forward articles of impeachment against Mr Trump.

Ms Pelosi and AOC do not talk to each other much. They have not spoken since earlier this year. But they are talking at each other in a power struggle that is now rippling through the party.

For Ms Pelosi's allies, her offhand dismissal in a newspaper interview over the weekend of AOC and allies who opposed the border security package was a necessary comeuppance for "the squad" of newcomers who are trying to push the party leftward.

In the speaker's world, the foursome lack what Ms Pelosi often calls "the currency of the realm": the power to turn their high-volume activism into a coalition of votes to pass legislation. The tweets from some of AOC’s staff against Democrats who supported the bill were seen as out of line.

But for fans of AOC, including some of her millions of social media followers, Ms Pelosi's remarks were nothing short of a patronising slap-back to four women of colour who represent the future of the Democratic Party, as well as a stark example of its generational and demographic transition.

Their four lonely votes against the bill were portrayed as a principled stand, with more to come.

"To dismiss any member's force, and particularly these four members who do have a tremendous following in the progressive base, I think is not the best thing," said Pramila Jayapal, the co-chair of the Congressional Progressive Caucus.

The ability to channel the influence of the newcomers into the currency of Congress may determine whether Ms Pelosi, six months into her new majority, continues her steady leadership or loses her firm grip.

Leaving the closed session Wednesday, Ms Pelosi told reporters, "I have no regrets about anything. Regrets is not what I do."