ABC’s Z. Byron Wolf reports:

Sen. John Ensign apologized to colleagues for his affair with a former campaign staffer at a weekly Republican caucus lunch, according to Senate Minority Leader Mitch McConnell.

Until last week Ensign would have stood with McConnell at the traditional Tuesday press conference that follows the party caucus lunches. But Ensign has resigned his leadership position and his replacement, Sen. John Thune, R-SD, stood behind McConnell instead.

MCCONNELL: Well, Senator Ensign obviously can speak for himself, but he spoke at our conference, apologized, and indicated that he was going to do his job.

QUESTION: Senator McConnell, (inaudible) that this has resolved the issue for now on behalf of the conference? Or do the unanswered questions need to be pursued perhaps in a Senate investigation?

MCCONNELL: No, I think the -- Senator Ensign will address whatever needs to be said from here on.

Ensign returned to the Senate to vote Monday night for cloture on a bill he sponsored that would create a sort of national tourism board to hock the US to the world as a tourist destination.

It’s a big deal for Las Vegas and Nevada and it was the first time we had seen Ensign in DC since he headed off a tell-all interview by the former staffer he cuckolded and admitted last week that he had an affair.

He voted in favor of cutting off debate on the bill, but he was one of only two Republicans to do so and the rest of the Republican caucus successfully blocked the bill. Ensign’s colleagues wanted more time to debate and amend the popular bipartisan bill, not because they opposed the bill, but because they wanted Democrats to allow more amendments. 9 of the 11 Republican cosponsors voted against cloture.

Senate Majority Leader Harry Reid, a Democrat from Nevada, who won a tough election face-off with Ensign in 1998 by a mere 428 votes, said this on-camera to reporters today:

REID: I know you have a lot of questions, but I'm not going to answer them, other than to say this. I have known the Ensign family for many, many years. Mike Ensign, Senator Ensign's father and I have been friends before I knew John Ensign. Mike Ensign is a wonderful man. He has a -- he's done a great job of coming from nowhere to become a very, very wealthy man, and he's done it through hard work, ingenuity, and he's a very bright man. Everyone knows that Senator Ensign and I had a very difficult race in 1998. We have become friends since then. I'm concerned about his family, and I hope he works his way through this. But as far as me commenting on any -- any more, I think I've said all I plan to say on Senator Ensign today.