The White House lashed out at House Republican leaders over immigration Tuesday after months of treading gingerly, revealing a sense of growing frustration inside the Obama administration with the sluggish pace of the reform effort.

The sudden change in tone represents a rhetorical escalation in the high-stakes immigration debate as the House deliberates on a series of small-scale proposals, eschewing the comprehensive approach adopted by the Senate and favored by the White House.

On Tuesday morning, Obama senior adviser Dan Pfeiffer wrote on Twitter that one House proposal amounted to “cruel hypocrisy” since it would leave millions of immigrants in the country illegally without a path to citizenship.

Later in the day, White House press secretary Jay Carney mocked House Speaker John A. Boehner (R-Ohio) after the GOP leader said at a news conference that no one has worked harder than he has to fix the nation’s border control system.

“The idea that you can, oh, I don’t know, declare yourself to have been more committed than anyone to improve our immigration system and then have nothing to show for it is a little laughable,” Carney said at his daily briefing.

For months, the White House chose to play a quietly supportive role, offering praise and gentle pressure as the Senate hashed out a comprehensive immigration bill that was approved last month by a bipartisan vote of 68 to 32.

But Boehner has said the House will not consider the Senate bill, frustrating President Obama, whose advisers are deliberating over how to ramp up the pressure on Republican leaders without risking potential support from moderates.

“If the House does, in the end, do the right thing and take action on comprehensive immigration reform and support it, then credit for that will accrue to the speaker as well as to other people,” Carney said at his briefing. “But thus far, we have not seen any evidence from House Republican leaders, anyway, of a commitment to comprehensive immigration reform as we’ve seen it from Republicans in the Senate.”

Boehner’s office reacted by noting that the speaker had called for the creation of a bipartisan working group on immigration early in Obama’s first term, while the president elected not to push for a sweeping immigration bill until his second.

“While the president was criticized by the Hispanic community throughout his first term for making empty pledges to address the issue, the speaker has been working quietly and without fanfare for years to foster a bipartisan consensus,” said Boehner spokesman Brendan Buck.

At a news conference earlier in the day, Boehner — who has not revealed his personal views on a path to citizenship for the nation’s estimated 11 million undocumented immigrants — was asked about his “hands off” approach to the issue.

“Nobody has spent more time trying to fix a broken immigration system than I have,” Boehner replied. “I talked about it the day after the election. I’ve talked about it a hundred times since. And while some may disagree about how we’re going about fixing a broken immigration system, it’s been a big goal of mine.”

The back-and-forth between the White House and Boehner came on a day that a House subcommittee held a hearing on the fate of young immigrants brought to the country illegally as children — a group commonly known as Dreamers, a reference to the failed Dream Act that would have given them a path to citizenship.

House Majority Leader Eric Cantor (R-Va.) has said he is working on a legislative proposal similar to the Dream Act that he may introduce later this month. Some Democrats and immigration advocacy groups have denounced the proposal, saying it would fail to address the fate of millions of other undocumented immigrants, including parents and relatives of those who would be helped.

Pfeiffer tweeted a link to an editorial in La Opinion, a Southern California newspaper aimed at Latinos, that was critical of Cantor’s proposal. The piece “nails the cruel hypocrisy of the GOP immigration plan: allow some kids to stay but deport their parents,” Pfeiffer wrote.

United We Dream, a youth advocacy organization, also protested Cantor’s proposal at a news conference at the Capitol. But other immigration proponents said they were encouraged that conservative Republicans were willing to discuss offering a path to citizenship for a portion of the undocumented immigrant population. They said it could be the first step in a larger deal with the Senate this fall.

At the hearing before the House Judiciary subcommittee on immigration, Chairman Trey Gowdy (R-S.C.), warned that reform proponents should not expect lawmakers to treat all undocumented immigrants the same.

“Let me say this as plainly as I can: Attempts to group the entire 11 million into one homogeneous group in an effort to secure a political remedy will only wind up hurting the most vulnerable,” Gowdy said.

Later in the hearing, Gowdy turned his attention to Pfeiffer, calling the Obama aide “a demagogic, self-serving political hack” for his morning tweet.