WASHINGTON (Reuters) - Democrats on the House energy committee on Tuesday asked Environmental Protection Agency chief Scott Pruitt to explain travel records that recently came to light, which showed he has taken frequent first-class flights at taxpayer expense.

FILE PHOTO - Environmental Protection Agency Administrator Scott Pruitt speaks during an interview with Reuters journalists in Washington, U.S., January 9, 2018. REUTERS/Kevin Lamarque

The Democrats wrote a letter asking Pruitt to provide a list of all dates where he traveled in first or business class, an explanation on how he followed guidelines for obtaining waivers for premium travel and the names of other staff who also traveled in premium class.

Complaints about travel arrangements by Pruitt and other Trump administration cabinet members re-emerged last week. Last year, Health and Human Services Secretary Tom Price resigned after reports that he used private jets for routine travel.

The documents cited by the lawmakers showed that Pruitt’s official travel has included first class flights for him and key staff, as well as the use of charter flights.

Pruitt did not immediately reply to a request for comment on the letter from members of the House panel. He recently said in a television interview that he was instructed to travel first class due to security threats and “uncomfortable” confrontations with other passengers.

The letter from the lawmakers asked Pruitt to explain why he believes security threats are reduced in first class cabins.

On Feb. 18, the Washington Post reported that Pruitt canceled a planned weeklong trip to Israel. A few days earlier, the newspaper had reported that he spent over $100,000 in taxpayer money for premium travel, based on records obtained by the Environmental Integrity Project.

That watchdog group on Friday obtained new travel records, shared with media, showing Pruitt and EPA employees spent upwards of $150,000 on premium commercial and chartered flights from March to August 2017.

“Americans deserve an EPA Administrator more dedicated to first class protection of human health and the environment than to luxury travel at taxpayer expense,” the letter said.

The letter also questioned a claim by EPA spokesman Jahan Wilcox, who told reporters Pruitt received a “blanket waiver” by ethics officials to enable him to travel first class.

The committee Democratic leaders, Representatives Frank Pallone, Paul Tonko and Diana DeGette, asked for answers by March 6.