Micheál Martin has denied the Government is trying to undermine NPHET by managing what interviews health officials carry out.
The Taoiseach says the change is to ensure a unity of voice across Government and the Department of Health.
He denied any NPHET members were blocked from appearing on radio shows over the weekend, despite guests pulling out of planned interviews.
Labour leader and Tipperary TD Alan Kelly says the government message is confusing;
"From my perspective and from the Labour Party's perspective the main confusion over the last week is not from NPHET, it's from you - and the government."
"When it came to antigen testing there was going to be subsidies, then all of a sudden the Minister announced on television that there wasn't going to be."
"There was a message sent out on Tuesday last at 6:15pm to schools regarding masks being mandatory - there was a U-turn on Monday."