Piers Morgan refuses to back down over Meghan Markle criticisms despite UK agency launching investigation

Piers Morgan said Tuesday that he will not apologize for expressing doubt about claims from Meghan Markle that she experienced suicidal thoughts after joining Britain's royal family.

Morgan's defiant response comes after the United Kingdom's regulatory agency governing telecommunications in Britain launched an investigation into "Good Morning Britain" over Morgan's comments.

How did Morgan respond?

After officially quitting "Good Morning Britain" on Tuesday after being ridiculed by his co-hosts for not believing Markle, Morgan said he will not apologize.

"On Monday, I said I didn't believe Meghan Markle in her Oprah interview. I've had time to reflect on this opinion, and I still don't. If you did, OK. Freedom of speech is a hill I'm happy to die on," Morgan tweeted.

"Thanks for all the love, and hate. I'm off to spend more time with my opinions," he added.

What is the background?

Morgan incited controversy on Monday while reacting to Markle's interview with Oprah Winfrey, when he doubted Markle's claim that her struggles with mental health were dismissed by the royal family.

"I'm sorry, I don't believe a word she says," Morgan said Monday on "Good Morning Britain."

When a co-host expressed dismay over Morgan's reaction, he doubled down. "I wouldn't believe her if she read me a weather report, and the fact that she's fired up this onslaught against our royal family, I think is contemptible," Morgan said.

Ofcom, the U.K. media regulator, revealed Tuesday it had opened an investigation into Morgan's comments after fielding more than 40,000 complaints.

"We have launched an investigation into Monday's episode of 'Good Morning Britain' under our harm and offence rules," the agency told Variety.

Why did Morgan quit?

The TV host stormed off the stage of "Good Morning Britain" on Tuesday after his co-hosts confronted him about his opinions.

ITV, the network that hosts "Good Morning Britain," later released a statement:

Following discussions with ITV, Piers Morgan has decided now is the time to leave Good Morning Britain. ITV has accepted this decision and has nothing further to add.

Prior to leaving the show, Morgan explained that he did not believe Markle generally, but specifically her claim that members of the royal family dismissed her mental health struggles because of negative optics.

Morgan clarified that he was not dismissing mental health struggles altogether.

"When we talked about this yesterday, I said, as an all-encompassing thing, I don't believe what Meghan Markle is saying generally in this interview and I still have serious concerns about the veracity of a lot of what she said," Morgan said.

"But let me just state for the record on my position on mental illness and on suicide. These are clearly extremely serious things and should be taken extremely seriously and if someone is feeling that way they should get the treatment and the help they need every time," he continued. "And if they belong to an institution like the royal family and they go and seek that help they should absolutely be given it."

"It's not for me to question if she felt suicidal, I am not in her mind and that is for her to say," Morgan added. "My real concern was a disbelief frankly ... that she went to a senior member of the royal household and told them she was suicidal and was told she could not have any help because it would be a bad look for the family."

"If that is true a) that person should be fired and b) the royal family have serious questions that need to be answered," Morgan said.