Having previously branded Piers’ behaviour “diabolical” on air, Alex has now followed up with his thoughts on Twitter.
He tweeted: “I wish I had the privilege to sit on the fence. In order for me to do that I would have to strip myself of my identity and that’s not something I can do.
“It’s not any of our places to pick apart claims of racism in order to make us to feel more comfortable.”
Earlier in the day, Alex had said of Meghan and Prince Harry on GMB: “They’ve had an overwhelming amount of negative press.
“You know, I watched the programme yesterday and, yes, they had some great press around the wedding, but what press is going to trash someone’s special day?
“There was bad press around the engagement before the engagement, and everything that has followed since has been incredibly damaging, quite clearly, to Meghan’s mental health and also to Harry.
“And I hear Piers say William has gone through the same thing but, do you know what, siblings experience tragedy in their life and one will be absolutely fine and brush it off and the other will not be able to deal with it so strongly and that is clearly what has happened with Harry in this situation.
“He walked behind his mother’s coffin at a tender, tender age, in front of the globe. That is going to shape a young boy for the rest of his life, so I think that we all need to take a step back.”
He continued: “And I understand that you don’t like Meghan Markle. You’ve made it so clear, a number of times on this programme. A number of times.
“And I understand that you’ve got a personal relationship with Meghan Markle and she cut you off, she’s entitled to cut you off, if she wants to. Has she said anything about you since she cut you off? I don’t think she has. But yet you continue to trash her.”
At that moment, Piers told Alex: “OK, I’m done with this,” before walking off set, adding: “Sorry no... can’t do this.”
Criticising Piers’ “diabolical behaviour”, Alex continued: “I’m sorry but Piers spouts off on a regular basis and we all have to sit there and listen. Six-thirty to seven o’clock yesterday was incredibly hard to watch. Incredibly hard to watch.
“This… he has the ability to come in here and talk from a position where he doesn’t fully understand.”
ITV had faced widespread calls to axe the divisive presenter after he cast doubt on Meghan’s revelation during her interview with Oprah Winfrey that she had experienced suicidal thoughts after joining the Royal Family.
ITV chief executive Dame Carolyn McCall confirmed on Tuesday that bosses were in conversation with Piers about his conduct.
Asked if Piers would lose his job or if she was backing him, she said she was “not making any comments on this.”
Piers’ comments have also been condemned by mental health charity Mind, who work with the broadcaster on its Britain Get Talking initiative.
“We were disappointed and concerned to see Piers Morgan’s comments on not believing Meghan’s experiences about suicidal thoughts today,” it said in a statement.
“It’s vital that when people reach out for support or share their experiences of ill mental health that they are treated with dignity, respect and empathy. We are in conversations with ITV about this at the moment.”
Good Morning Britain airs weekdays at 6am on ITV.