The Presbyterian Church (USA) has turned on Donald Trump who is still feeling the impact of his row with Pope Francis over his suggestion he was "not a Christian" for proposing a border wall with Mexico.

But the conservative credentials of the Republican front runner are not convincing to one foreign commentator who has labeled him a "complete fake."

The leadership of Presbyterian church he was born into says his extreme views on how to deal with immigration are out of line with its teachings.

Rev. Gradye Parsons, the most senior elected official of the Presbyterian Church (USA) to which Trump was baptized as a child, said that the Bible is clear:, stating followers of the faith have to care for the needy.

"Donald Trump's views are not in keeping with the policies adopted by our church by deliberative process," he said.

In an interview with the UK's Guardian newspaper, Parsons said that the Presbyterian church had voted several times since the 1990s in its national general assemblies in favor of comprehensive immigration.

These allowed for granting a route to legal status for the 11 million undocumented people currently living in the United States.

"Our official policy is to encourage immigration reform," noted Parsons.

He explained that the founding narrative of Christianity contains a commitment to those most in need - widows, orphans, the oppressed and the alien.

"It is clear that God wants us to act on behalf of the stranger. Jesus himself and his parents had to flee the country for their lives when he was born – there are lots of parallels."

POPE TRIGGERS US PRESIDENTIAL DEBATE

The Pope sparked a fierce response from U.S. Republican Party presidential candidate hopeful Trump when, without naming him, he questioned his Christian credentials. His comments immediately became part of the U.S. presidential debate.

"Anyone, whoever he is, who only wants to build walls and not bridges is not a Christian," Francis said on the papal flight from Mexico in answer to a question from a journalist.

"Vote, don't vote, I won't meddle. But I simply say, if he says these things, this man is not a Christian," Francis said.

"We need to see if he really said them and for this I will give him the benefit of the doubt."

On a campaign rally stop in South Carolina, in which Trump swept to victory over the weekend in its Republican primary, Trump hit back saying, "For a religious leader to question a person's faith is disgraceful.

"I'm proud to be a Christian, and as president I will not allow Christianity to be consistently attacked and weakened, unlike what is happening now with our current president," he said Trump.

On Feb. 19 the explained that Francis' comments had not been intended as a personal attack.

Trump himself backtracked on some harsh criticism of Pope Francis saying later "I have a lot of respect for the Pope. He has a lot of personality and I think he's doing a very good job, he has a lot of energy."

But the spat has reopened questions about Trump's standing in the eyes of the religious community, the Guardian commented.

It noted that the Republican primary race, in which Trump leads his nearest rivals Ted Cruz and Marco Rubio, moving to the deep south exposes him where evangelical conservatives wield considerable sway.

TRUMP CONFIRMED IN PRESBYTERIAN CHURCH

Trump was confirmed as a child at the First Presbyterian Church in Jamaica, Queens, and has always self-associated as a Presbyterian.

He says he now worships at the Marble Collegiate Church in Manhattan, part of the Reformed Church in America denomination, the Guardian reported.

Parsons, who is the "stated clerk" or chief executive of the 1.6 million-strong Presbyterian Church in the United States, said he would stop short of the Pope's suggestion that Trump's views on immigration decreed him "not a Christian."

But he noted that "Biblical mandates are important - how people care for the oppressed and the alien acts as a marker of whether they are following their faith."

In his campaign Trump triggered ire for his comments on religious groups and institutions including Muslims, who he wants to ban from visiting the United States.

"But perhaps one unexpected indication as to why he won is Trump's strident hatred of Muslims," speculated the U.S. online publication truthdig.

"Some 75 percent of GOP [Republican] primary voters in South Carolina support his bizarre and unconstitutional idea of banning Muslims from traveling to the United States.

"That is nearly twice the national average on this issue (46 percent) and more than the average among Republicans nationally (66 percent)."

Truthdig cited a sounding by Public Policy Polling that found that South Carolina Republican voters supporting Trump as outliers among party supporters in the state.

"Some 80 percent of them want to ban Muslims from traveling to the U.S., and about a third of Trump supporters want to ban gays from coming here as well."

Trump's conservative credentials may be wowing Republican voters in the primaries but they look totally unconvincing to the Austalian Daily Telegraph's Tim Blair who denounced him in a piece headlined, "Candidate Donald Trump is a complete fake, his right-wing pose is a cynical act."

Blair opined that Trump has a huge supporter base among voters and pundits "weary of the usual politically correct and evasive politicians" and that his stance on Muslim immigration and border protection "strike a resonant chord throughout middle America."

"It's just that Trump is a complete fake. He's less a viable presidential candidate than a marketing exercise for the Trump brand. He's running as a hard-core conservative solely because that role happens to be vacant.

"If the rest of the field shifted right, you get the feeling that Trump would start quoting Castro and wearing a Che Guevara T-shirt."