File: Former Arkansas governor Mike Huckabee (MANDEL NGAN/AFP/Getty Images)

Mike Huckabee is leaving Fox News to decide whether he wants to run for president.

The Republican former governor of Arkansas said that Saturday night's episode of "Huckabee" is the last.

"There has been a great deal of speculation as to whether I would run for President. And if I were willing to absolutely rule that out, I could keep doing this show. But I can't make such a declaration," Huckabee said at the end of the show. 

He said the swirling speculation about whether he will run or not is not fair to Fox.

"As much as I have loved doing the show, I cannot bring myself to rule out another Presidential run," he said. "I say goodbye, but as we say in television, stay tuned. There’s more to come."

(Past coverage: Mike Huckabee rebuilds political team with eye on another presidential run)

Huckabee has hosted the show for more than six years. Ending his show is a requirement for laying the groundwork for a presidential run. As a policy, Fox ends relationships with commentators who form exploratory committees or seriously intend to run for office.

"I have to be very careful about this," Huckabee told The Post in November.

The network said it has "amicably parted ways" with Huckabee. It was "in the best of both of their interests," a network spokeswoman said.

"I agree with Fox, that this is the right thing and now is the right time," Huckabee said, noting that he won't make a decision about running until late spring.

Huckabee’s decision instantly shakes up the emerging race for the Republican presidential nomination. Particularly in Iowa, where Huckabee surged from the bottom of the polls in 2008 to win the presidential caucuses, his move will have consequences for other conservative contenders as they plot their own possible paths.

Sen. Ted Cruz (R-Tex.), Sen. Rand Paul (R-Ky.), and Gov. Rick Perry (R-Tex.) have been courting Iowa’s evangelical voters for months, believing the support of that bloc is up for grabs. Huckabee’s entry would make the battle for those conservative votes a messy and crowded contest, with the Arkansan bringing a deep base of support from his 2008 campaign with him. Huckabee drew more favorable responses than any other potential candidate during an exit poll this year in Iowa, with 19 percent of Republican voters there saying they wanted him to be the next presidential nominee.

Huckabee’s decision comes after months of private discussions with his family, his advisers, and his top donors about his political future and whether he should leave the Fox program, which has provided him with a hefty salary and enabled him to purchase a beachfront mansion in Florida.

Huckabee’s political circle from his 2008 campaign largely remains intact, with Chip Saltsman, the longtime political strategist who had managed his 2008 campaign, on board, along with Bob Wickers, another confidant. Alice Stewart, a veteran of Huckabee’s 2008 campaign, has been handling communications. Sarah Huckabee, the former governor’s daughter, is also advising him. Chad Gallagher, a trusted aide, is currently managing Huck PAC, a political-action committee.

A Huckabee aide, who asked not to be named because the aide is not authorized to speak publicly, said Saturday that Huckabee would not form a presidential exploratory committee before April. Instead, the aide said, Huckabee will work with his non-profit group and his PAC on various projects, and will only formally create a new political entity if he decides to launch a campaign.

An early test for Huckabee’s 2016 ambitions will begin later this month when he goes on a national tour to tout his new book, “God, Guns,  Grits and Gravy,” a 272-page manifesto on politics and culture. A Huckabee aide not authorized to speak publicly said his promotional road trip will coincide with meetings and planning for his possible presidential campaign, and give Huckabee an opportunity to brush up on his retail political skills.

Huckabee will have competition on the bookstore shelves. Rivals Cruz, Paul, and Sen. Marco Rubio (R-Fla.) all have their own books in the works. Maryland neurosurgeon Ben Carson, a tea party favorite, has a book offering life lessons for teenagers scheduled to be released in February.

Huckabee’s team has been scouting office locations in Little Rock, Ark., since November, and an aide said Saturday that the campaign, if made official, would be based there. But aides said no final decisions on a location for a headquarters have been made.

Huckabee’s shift from semi- retirement to being on the cusp of another presidential run began in July 2013, based on interviews with his allies in November and on Saturday. As Huckabee sat on the beach one day with his family, he was joined by Saltsman.

According to the interviews, Saltsman asked Huckabee whether he was interested in running again. Huckabee shrugged and said he was not sure. Saltsman replied that if he had any inclination to do it, he needed to start mapping out a run as soon as possible in order to keep up with his potential rivals. Saltsman’s parting message: Call me when you’re ready. A couple of days later, Huckabee rang Saltsman and said, “Let’s go.”

Huckabee’s standing among religious conservatives has grown since he last was on the presidential campaign trail. Earlier this year he led more than 100 pastors and GOP insiders from early primary states on a 10-day overseas trip with stops in Poland and England.

Bob Vander Plaats, a power broker among Iowa evangelicals, said in November, “Huckabee is positioned very well. People love him. He left but never left. He’s on Fox News in people’s living room on Saturday or Sunday.”

Added Russell Moore, the head of the policy arm of the Southern Baptist Convention, also in November, “When I ask pastors about who they like most, they usually mention him.”

There are questions in Huckabee’s orbit about his fundraising prowess, in spite of the signs that he is doing more this time around to woo the party’s biggest donors. Huckabee spent part of November holding meetings with powerful GOP financiers in Las Vegas, New York, and California, gauging their interest in being bundlers and asking for pledges of five-to-six figure donations to his aligned organizations. In December, he held meetings in Little Rock and Destin, Fla., near his Gulf Coast home, to discuss his potential campaign.

“He’s one of the best retail politicians ever,” said Ed Rollins, a former Huckabee adviser, in a November interview. “The question is: is that enough? Can he convince Republicans that he is the strongest candidate to go up against Hillary Clinton? Can he raise the money to build a national infrastructure?”

Huckabee could also face challenges engaging anew in the fractious, modern-day GOP. Huckabee said in 2013, for instance, that the Common Core State Standards, which have infuriated many tea party conservatives, were “near and dear to my heart.” He has since walked back those comments and called the program “toxic.”

Huckabee, a 59-year-old former Baptist preacher, served as Arkansas governor from 1996 to 2007, and is known as one of the Republican Party’s fiercest defenders of social conservatism. Anti-abortion and a critic of same-sex marriage, he has carved out a powerful space in the party as a blunt spokesman for conservatives frustrated with elements of the culture and often with the GOP establishment’s approach to moral issues.

As an Arkansan, Huckabee has also known the Clinton family for years and seen their political operation in action—a history his advisers believe gives him a singular perspective on Hillary Clinton.

“Nobody knows the Clintons better than Mike and Clinton tried to beat him every time. He matches up well against Hillary Clinton. He has the common touch and he can speak to income inequality,” said Huckabee adviser Bob Wickers in November.

When Huckabee ran in 2008, he found it difficult to sustain his initial momentum. Three months after the Iowa victory, Huckabee ended his campaign and Sen. John McCain (R-Ariz.) would go on to win the Republican presidential nomination.

Huckabee’s decision to leave Fox comes as former Florida governor Jeb Bush (R) has been putting aside his business interests and his board work to seriously consider a 2016 presidential run. Unlike Huckabee, however, Bush will not attend Rep. Steve King’s Iowa Freedom Summit in Des Moines later this month. Bush differs with King, a conservative hard-liner, on immigration policy.

Huckabee called his show "the ride of a lifetime" and said he has never had so much fun.

"I also realize that God hasn't put me on earth just to have a good time or to make a good living, but rather God's put me on earth to try to make a good life," he said.

On its last episode the former governor played guitar with country music duo the Swon Brothers, discussed his frustration with President Obama, his decision-making while the chief executive of Arkansas, law enforcement and his belief that that there isn't much governing coming out of Washington.

Huckabee said he hopes to see a return of "the fine art of governing" in 2015.

"And if we don't, I'll say what parents often say to their kids, 'don't make me come up there,'" he said.

Tom Hamburger contributed to this story.