The ABC’s managing director has apologised to Q&A host Stan Grant — who has said he felt unsupported — as a question hangs over the TV journalist’s future.

Grant is stepping away from his role as host of the program, citing exhaustion with persistent racial abuse.

But in an opinion piece published by the ABC, Grant left the door open for a return, writing: “On Monday night I will present my Q+A program, then walk away. For how long? I don‘t know.”

The ABC is scrambling to replace him, with RN Breakfast host Patricia Karvelas and ABC Radio Melbourne’s Virginia Trioli among those speculated to take the seat.

The ABC’s boss David Anderson sent an email to staff in which he apologised to Grant.

“How the ABC supports people in these moments is important. Stan Grant has stated that he has not felt publicly supported. For this, I apologise to Stan.

“The ABC endeavours to support its staff in the unfortunate moments when there is external abuse directed at them.”

Mr Anderson said Stan had the ABC’s “full support”.

“And he has always had our full support,” Mr Anderson wrote.

“Stan makes an enormous contribution to conversations of national importance.”

Grant last week expressed frustration at the ABC’s executives, saying none had publicly refuted lies written and spoken about him.

“I don’t hold any individual responsible; this is an institutional failure,” he said.

In his email, Mr Anderson said he agreed with a recommendation from the ABC’s Indigenous advisory committee to review how the broadcaster responded to racism towards staff.

He said anti-ABC reporting from some commercial media outlets had been “sustained and vitriolic”.

“This has real-world consequences for ABC presenters and journalists who are personally attacked and vilified,” he wrote.

Grant made the decision to leave Q&A last week after racism against him intensified following his involvement in the public broadcaster’s coverage of the King’s coronation.

The veteran correspondent was invited to participate in an ABC TV discussion on coronation day, during which he pointed out that the crown represents the invasion and theft of Aboriginal land.

While the ABC’s news director Justin Stevens had been a “support and a comfort” according to Grant, the national broadcaster had its own legacy of racism.

In a statement last week Mr Stevens said the broadcaster stood by Grant and the abuse was “abhorrent and unacceptable”.

Threats against Grant had been referred to police while a formal complaint had also been lodged with Twitter.

The ABC Ombudsman would investigate editorial complaints regarding the panel, Mr Stevens said.