This morning Bridges said he knew nothing about the ad, didn't know Brooks, and didn't know the story behind the ad, adding that it probably breached electoral law because it was not authorised by the party.
Under the law, any ad that promotes voting for a particular party has to be signed off by that party.
The Electoral Commission is now investigating.
Bridges said he spoke to Luxon at the end of last week but was not actively courting him.
He wouldn't say if he had initiated the call.
"I didn't over analyse that part of it ... You know how many calls I do a day? We might be calling 50 or 60. I don't think a whole lot about who rings who. I appreciate how exciting it is to you, but that's not uppermost on my mind.
"Chris is a talented guy, he's had a distinguished business carrier. He's a good guy. Now it's a case of waiting to see what happens."
Asked whether Luxon would make a good party leader or Prime Minister, he said: "Let's see what happens. Let's be fair to the guy and let's see if he gets to Parliament first."
He said he knew Luxon personally, as well as from his time as Transport Minister, but he would not say whether they had talked about Luxon's future prospects with National.
Luxon is the chair of the business advisory group that advises Prime Minister Jacinda Ardern, and Ardern has said she was happy for him to continue in that role until he leaves Air NZ in late September.
She had no concerns about whether Luxon might run for the National Party in the future.
"Obviously he has a role still to fulfill at Air NZ and I imagine his mind will rightly be on that through to September," Ardern said.
Luxon has said it was not an issue to indicate support for National while serving on the business advisory council.
