The Aged Care Association is renewing its call for the National Party to support a hike in wages for caregivers in private rest homes and aged care facilities.
Caregivers employed by district health boards earn $17.50 an hour, while the 30,500 employed in private rest homes earn on average $15.30 an hour.
Chief executive of the Aged Care Association Martin Taylor said the pay gap must be addressed.
"We are not valuing the elderly as we should - and it's an injustice. Caregivers should get more wages and we should be funded so that we can pay higher wages. They deserve it, the elderly deserve it."
Mr Taylor said National was the only major political party that had not confirmed its support for pay parity in the industry.
The association launched a campaign in June to put aged care on the agenda for the general election.