WASHINGTON >> Lawmakers assailed Environmental Protection Agency chief Scott Pruitt today for the ethics and spending scandals that have prompted bipartisan calls for his ouster. On the defensive, the EPA chief blamed “half truths” and “twisted” allegations, an effort to undermine the Trump administration’s anti-regulatory agenda.

The public grilling at a House hearing came as support has eroded for Pruitt among fellow Republicans after a nearly monthlong hammering of negative headlines about outsized security spending, first-class flights and a sweetheart condo lease. Even Republicans who support Pruitt’s policy agenda said his apparent lapses could not be ignored.

Democrats excoriated him as the hearing opened. “You are unfit to hold public office,” said Rep. Frank Pallone of New Jersey. Rep. Paul Tonko said of the allegations, “the more we have learned, the worse they get,” and told Pruitt he was “never fit for this job.”

President Donald Trump has continued to stand by his EPA chief, but behind closed doors, White House officials concede Pruitt’s job is in serious jeopardy. In the last week, a growing list of Republican lawmakers has joined the chorus of Democrats calling for new investigations into Pruitt’s actions.

Pruitt only addressed the allegations in passing in his opening statement, acknowledging merely that “there’s been a learning process,” and adding, “Facts are facts, fiction is fiction.”

Pruitt faced back-to-back hearings today, called formally to consider EPA’s budget.

Pruitt has faced a steady trickle of revelations involving pricey trips in first-class seats and unusual security spending, including a $43,000 soundproof booth for making private phone calls. He also demanded 24-hour-a-day protection from armed officers, resulting in a swollen, 20-member security detail that blew through overtime budgets and racked up expenses approaching $3 million.

White House press secretary Sarah Huckabee Sanders said before the hearings that officials were “evaluating these concerns and we expect the EPA administrator to answer for them.”

Pruitt in the past has often sought to deflect questions about any missteps by blaming his subordinates.

Asked about his frequent use of premium-class airfare in February media interviews, Pruitt said, “I’m not involved in any of those decisions.” The administrator said his security chief made the decision for him to fly in first class after an unpleasant interaction with another traveler raised safety concerns.

Pallone told him at the hearing: “The buck stops at your desk.”

Pruitt’s troubles began in earnest last month, when ABC News first reported he had leased a Capitol Hill condo last year for just $50 a night that was co-owned by the wife of a veteran fossil fuels lobbyist whose firm had sought regulatory rollbacks from EPA.

Both Pruitt and the lobbyist, Steven Hart, denied he had conducted any recent business with EPA. But Hart was forced to admit last week he had met with Pruitt at EPA headquarters last summer after his firm, Williams & Jensen, revealed he had lobbied the agency on a required federal disclosure form.

EPA’s press office has declined to discuss the meeting.

Today’s hearings were Pruitt’s first major appearance since a Fox News interview in early April that was widely considered to be disastrous within the West Wing.

Before the hearings, when pressed on reports of significant raises awarded to two close aides he had brought with him to EPA from Oklahoma, Pruitt denied having any role in the decision. Documents later showed Pruitt’s chief of staff signed off on the pay increases, indicating he had the administrator’s consent.

A lawyer and former Oklahoma attorney general, Pruitt is known to prepare meticulously for congressional hearings, with his office schedule showing he often blocks off hours huddled with top political aides.

An administration official confirmed that Pruitt declined an offer of White House assistance in preparing for the latest congressional hearings. The official spoke on condition of anonymity to discuss sensitive internal conversations.

Republican Sens. John Barrasso of Wyoming and John Thune of South Dakota said before the hearings that Pruitt faces “serious questions” about his use of taxpayer money.

“I want to make sure taxpayers are getting value for their dollars, make sure money is being spent appropriately. So there continue to be serious questions,” said Barrasso, chairman of the Senate Environment and Public Works Committee. “We’ll see what comes out of the hearings.”