BBC's Emily Maitlis on Tuesday confronted former White House press secretary Sean Spicer, arguing that his actions while serving as the top spokesman for President Trump "corrupted discourse for the entire world by going along with" the president's lies.

Maitlis made the statement during BBC Newsnight as she interviewed Spicer, who is promoting his new book, "The Briefing."

In a wide-ranging interview, Maitlis pressed Spicer on his frequent defenses of Trump's actions, including Spicer's statements on the size of Trump's inauguration crowd in 2017.

Maitlis accused Spicer and White House counselor Kellyanne Conway of engaging in damaging rhetoric by creating a "second version of the truth" by saying Trump's inauguration-crowd size was the largest in history.

"We all make mistakes," Spicer responded, adding that he would love a "do-over on that one."

"There are things that I absolutely would love to do over. There were days that were extremely lonely in that job because I screwed up."

But Maitlis used it as an example of a "corrosive culture."

"It became a joke. It became something that defined you," she said. "You joked about it when you presented the Emmy awards. But it wasn't a joke. It was the start of the most corrosive culture. You played with the truth, you led us down a dangerous path. You have corrupted discourse for the entire world by going along with these lies."

Spicer pushed back against that criticism, saying that Maitlis's comments ignored the "many false narratives and false stories that the media had perpetrated."

Maitlis later said that Trump spouts "lies or half-truths" and that Spicer was his agent by working as his press secretary.

Spicer was appearing on the show to promote his new book on his time in the Trump administration, which was known for his contentious relationship with the media.

ABC News White House correspondent Jonathan Karl has slammed the book in a review for The Wall Street Journal, saying that it reads "much like his tenure as press secretary: short, littered with inaccuracies and offering up one consistent theme: Mr. Trump can do no wrong."