Republican Mike Miller (search) has endorsed his former rival, U.S. Sen. Lisa Murkowski (search), but says she still must work to draw conservative voters who preferred him in the primary last month.

The endorsement upholds a pledge Miller and Murkowski signed in May.

Miller, a former state Senate president from North Pole, billed himself as a "trusted conservative" as he sought to be the Republican candidate for Senate.

Miller told the Anchorage Daily News that he and Murkowski differ on taxes, guns and abortion — all issues he criticized her on during the primary. However, issues Alaskans care about will suffer if Democrat Tony Knowles (search) wins the election and Republicans lose control of the Senate, he said.

Murkowski beat Miller by more than 20 percentage points in the Aug. 24 primary and now faces Knowles in the general election in November.

Miller said he will ask people who worked closely with him to support Murkowski. Backers such as Lt. Gov. Loren Leman, former Anchorage Mayor Tom Fink and state Sen. Lyda Green already have pledged themselves to Murkowski.

As for the conservative Alaskans who voted for him, Miller said, he cannot promise they'll make the switch.

"I certainly am supporting Lisa and publicly saying that," Miller said. "However all those folks are independent-minded and they are going to do what they are going to do, and I'm not going to brow beat anybody into a position ...

"Lisa's going to have to talk to these folks and she's going to have to bring them along," he said. "She's going to have to bring them along by telling them where she stands on the issue. She is the candidate now, I am not."

The Murkowski campaign said it would welcome whatever help Miller offered.

"We've heard from a lot of his supporters, both just people that voted for him and the people who are running his campaign, that they are now firmly behind Lisa and the goal is unity and victory in November and ensuring Tony Knowles is not allowed to become a senator," said spokesman Elliott Bundy.

Knowles spokesman Matt McKenna said he did not think Miller's endorsement will help Murkowski.

"I don't think that politicians endorsing other politicians makes a difference to Alaska voters," McKenna said.

Miller said that the primary was contentious but that he and Murkowski do not resent each other.

"You don't get into the sport if you have a very thin skin because it's a very brutal game," he said.