Labor has referred MP Stuart Ayres to the corruption commission over his $12 million campaign promise to the Penrith Panthers to build sports facilities that were used to finance a conference centre.

It comes after revelations Mr Ayres did not disclose his membership of the club, took thousands in donations from the Panthers, pushed for the deal to go through weeks before the 2019 election and insisted his signature be taken off the funding agreement.

Penrith MP Stuart Ayres at NSW Parliament estimates answering questions about $12m funding from his sports department. Credit:James Brickwood

Donations worth $4500 from Penrith Panthers in the lead up to the 2015 election had "absolutely" no effect on the decision to make a $12 million election commitment to a sports and conference centre at the club, Mr Ayres said.

"Panthers haven't made a donation in return for investment," the former sports minister said on Tuesday. "I think if you went back over time you'd see that they have donated to many local members across both sides of politics."