Channel 4 News/YouTube
MacKenzie wrote on Monday that he could "hardly believe my eyes" when he saw Manji presenting Channel 4 News' studio coverage of the attack in a hijab on Friday last week.
"Was it appropriate for her to be on camera when there had been yet another shocking slaughter by a Muslim?" asked MacKenzie, a former editor of The Sun.
"Was it done to stick one in the eye of the ordinary viewer who looks at the hijab as a sign of the slavery of Muslim women by a male- dominated and clearly violent religion?
Manji responded to the comments for the first time on Tuesday in a written piece for The Liverpool Echo. She said MacKenzie remarks had "undefined sentiments" and spread "ill-informed, irresponsible, and malevolent invective to millions of readers."
THE TRUTH: I'm here to stay, Kelvin MacKenzie https://t.co/5cw82GpCKL
- Fatima Manji (@fatimamanji) July 19, 2016
"Kelvin MacKenzie has attempted to smear 1.6 billion Muslims in suggesting they are inherently violent. He has attempted to smear half of them further by suggesting they are helpless slaves. And he has attempted to smear me by suggesting I would sympathise with a terrorist," she wrote.
Manji added: "THE TRUTH? I confess. I pi**ed on Kelvin MacKenzie's apparent ambitions to force anyone who looks a little different off our screens, and I'll keep doing it."
The latter quote is a reference to an infamous front page - headlined "The Truth" - The Sun published under MacKenzie's editorship after the Hillsborough disaster in 1989, when 96 Liverpool fans lost their lives as a result of overcrowding at the Sheffield football stadium.
This symbolism was all the more pronounced by Manji's decision to write her response for The Liverpool Echo, which has been a prominent campaigner over the Hillsborough disaster.
A spokesman for The Sun is yet to respond to Business Insider's request for comment.
'Offensive' and 'completely unacceptable'
MacKenzie's comments have sparked 1,400 complaints to British press regulator the Independent Press Standards Organisation. Channel 4 News has also condemned the column.
It said: "The comments published in The Sun by Mr MacKenzie are offensive, completely unacceptable, and arguably tantamount to inciting religious and even racial hatred.
"It is wrong to suggest that a qualified journalist should be barred from reporting on a particular story or present on a specific day because of their faith. Fatima Manji is an award-winning journalist. We are proud that she is part of our team and will receive, as ever, our full support in the wake of his comments."