People Before Profit TD Brid Smith says the outsourcing of the screening programme is at the heart of the the CervicalCheck scandal.
She was reacting to revelations that more women have been caught up in the controversy, on top of the 800 revealed on Thursday.
The HSE says it has known since February about a computer glitch, which meant hundreds of women who underwent CervicalCheck screening were not given their results.
Deputy Smith says outsourcing to US labs isn't working even though she's in favour of screening:
"This is potentially women's health and lives that are at risk," Deputy Smith said.
"I should say at the outset, I am a complete supporter of screening. Cancer screening is really important and I don't think we should be undermining the notion of cancer screening - the service can yield a lot for women's health.
"The problem is we have outsourced cancer screening for the last 10, 11 (or) 12 years," she added.