A Mississippi gubernatorial candidate defended his refusal to spend time alone with a female reporter unless she was accompanied by a male colleague - a move which she branded 'sexist.'

Reporter Larrison Campbell, 40, asked to ride with Republican state Representative Robert Foster, 36, on a 15-hour campaign trip but was told by his staff on July 7 that a male colleague would have to accompany her.

Campbell, who covers politics with the online news site Mississippi Today, said she was told 'the optics of the candidate with a woman, even a working reporter, could be used in a smear campaign to insinuate an extramarital affair.'

Mississippi gubernatorial candidate Robert Foster, (left), defended his refusal to spend time alone with female reporter Larrison Campbell, (right), unless she was accompanied by a male colleague

Foster and Campbell went head-to-head on the matter in an interview with CNN's John Berman on New Day, where Foster claimed that being alone with a woman would go against his Christian values.

Foster said: 'I didn't want to end up in a situation where me and Ms. Campbell were alone for an extended period of time throughout that 15 or 16 hour day, and so out of precaution, I wanted to have her bring someone with her - a male colleague.

'The other thing I think it's important to point out is that this is my truck, and in my truck, we go by my rules and that's my rule.'

Larrison Campbell criticized his remarks, saying no other candidate had a rule like this and it amounted to sexism.

She responded: 'Look, we got to call this what it is: when a woman isn't given access to the same things that a man would be given access to, it's sexism.'

Foster previously claimed that he and his wife follow the 'Billy Graham Rule,' a practice attributed to the late evangelical preacher whereby a husband does not spend time alone with any woman other than his wife.

Berman questioned him on his stance and Foster claimed that he would allow the same access to a male reporter alone.

Campbell was interviewed on CNN's John Berman on New Day and said Foster's decision amounted to 'sexism' as he said he would allow a male reporter to spend time with him

Larrison Campbell looked bemused and criticized Foster's remarks, saying no other candidate had a rule like this and she was simply trying to do her job

Foster added: 'I trust myself completely, but I don't trust the perception that the world puts on people when they see things and they don't ask the questions, they don't look to find out the truth.

'Perception is reality in this world, and I don't want to give anybody the opinion that I'm doing something that I should not be doing,' he said.

Campbell countered why there should be an 'onus' on her to bring a colleague along for an interview when she is simply trying to do her job.

'Why is it my responsibility to make you feel comfortable about something that, you know, that again as your campaign director said on the phone with me, is this weird request that you have?,' she said.

'Let's go back to the appearance of impropriety thing. Why does it appear improper for a man to be with a woman? I mean, why wouldn't a gay affair be construed if he were with a man?

'Unless, at the end of the day, what you're saying here is a woman is a sexual object first and a reporter second,' Campbell added.

Foster responded to the story on social media on Wednesday, Tweeting: 'As I anticipated, the liberal left lost their minds over the fact I choose not to be alone with another woman. They can't believe, that even in 2019, someone still values their relationship with their wife and upholds their Christian Faith'

Foster (left) wrote that he and his wife, Heather, (right), follow the 'Billy Graham Rule,' a practice attributed to the late evangelical preacher not to spend time alone with any woman other than his wife. Foster did not address how such a practice might prevent him from working one-on-one with women in official capacities, should he be elected governor

Foster then claimed that he was a married man and that he would put his marital vows above other people's feelings.

He told Campbell: 'I apologize to you for that, that it may hurt your feelings, but I would much rather uphold my vows to my wife over anyone else.

'I’m not ever going to be put in a situation with any female to where they could make an accusation against me and there’s not a witness there to refute that accusation.'

He added: 'I'm a married man and I made a vow to my wife, and part of the agreement that we've also made throughout our marriage is that we would not be alone with someone of the opposite sex throughout our marriage, and that is a vow that I have with my wife.'

'I put that and my faith and my religion, that is the reason why we have that vow, above anyone else's feelings, including yours and I apologize to you for that.'

Campbell asked why there should be an 'onus' on her to bring a colleague along for an interview to make Foster feel comfortable

Campbell first reported on the incident on the online news site Mississippi Today, and has often reported about Foster's political life.

She had called him directly to arrange the ride-along, as Mississippi Today was doing with each candidate for governor ahead of the Republican primary, including former state supreme court chief justice Bill Waller and current Lt. Gov. Tate Reeves.

Due to their professional familiarity with one another Campbell told Poynter she was surprised to hear back instead from Foster's campaign director, Colton Robison.

'Hey, I have a weird request,' Robison said, according to Campbell. 'We’re going to need you to bring a male colleague along.'

'At first, I didn’t even know what to think; it was such an out-of-left field thing,' told Poynter on Wednesday. 'And then as they explained it, I was like, "Oh wait, you’re serious and this is just because I’m a woman."'

'They said because you’re a woman, he wants to avoid any impropriety,' Campbell said.

'Anything that could make him look guilty of having an improper relationship with a woman.

'Apparently being seen with a woman in a work context is so unusual people would assume I was there to have an affair with him. I said that to them. I said, "There is no reason other than the fact that I’m a woman that would imply an inappropriate relationship." And Colton said, "Yeah."'

Foster holds right-wing positions such as opposing changes to the Mississippi state flag, which features a Confederate symbol which is strongly associated with slavery in the U.S.

In a text to Campbell on Wednesday, Foster wrote that he does not consider refusing to allow her access to a ride-along sexist.

'I am confident that a majority of Mississippians understand that this isn’t about gender discrimination, rather a personal conviction,' Foster told Mississippi Today on Wednesday.

'I am a God-fearing man devoted to my wife and even though having a ride along with me wouldn’t be in itself immoral, the Bible teaches us to refrain from the appearance of impropriety. That’s what I did, and I’m sticking to my guns.'

Campbell addressed the issue again on Twitter, writing as part of a thread: 'I have yet to hear of a female politician (don't y'all forget those exist!) who's invoked the Billy Graham rule when dealing with male colleagues.

'And this gets at the "perception is everything" statement I got from Foster's campaign that kicked off everything.'

Foster maintained that his rule is 'very professional', as other male politicians have followed the Billy Graham rule.

Vice President Mike Pence has made a point of not having a meal with an unaccompanied woman.

Before he was vice president, Mike Pence in 2002 told The Hill he 'never eats alone with a woman other than his wife.'