Hundreds have complained about The Sun columnist Kelvin MacKenzie's article criticising Channel 4 News for allowing a hijab-wearing journalist to present a report on the Nice massacre.
Stating that he could "hardly believe my eyes" when he saw Fatima Manji presenting, MacKenzie asked in his Monday column: "Was it appropriate for her to be on camera when there had been yet another shocking slaughter by a Muslim?"
The column sparked outrage, with Channel 4 News accusing MacKenzie, a former editor of The Sun, of "inciting religious and even racial hatred".
Ex-Conservative Party chairman and foreign minister Baroness Warsi wrote to The Sun's editor in chief Tony Gallagher, branding it a "divisive column".
The Independent Press Standards Organisation (Ipso) said it had received more than 300 complaints, which still have to be assessed, related to accuracy, harassment and discrimination.
A spokesman for The Sun said it was making "no comment" on the issue.