People hold up placards and Union flags as they gather for a demonstration organised by the Campaign Against Anti-Semitism outside the head office of the British opposition Labour Party in central London on April 8, 2018. TOLGA AKMEN | AFP | Getty Images

An infamous political tale tells of the occasion when former U.K. Prime Minister Tony Blair once wanted to discuss his faith in public but was interrupted by his director of strategy and communications Alistair Campbell who abruptly told him: "We don't do God." The curt riposte to Blair's desire to talk about his Christian faith reflects a general attitude in the U.K. — both among the political establishment and the general public — that politics and religion don't mix well. In the case of the forthcoming U.K. election on Thursday December 12, however, political parties have been unable to dodge religion with controversies over discrimination coming to the fore for both the Conservative and Labour parties. The bigger prominence of religion in the 2019 snap election, one which will decide the direction the U.K.'s departure from the EU takes, is more to do with identity politics, experts say. "We're not a mainstream religious country," Vince Cable, the former leader of the Liberal Democrats, told CNBC Tuesday. "This isn't America, it's not Poland, we're a fairly secular country so it's not the vast majority of people wanting to express a religious view. But I think it's one manifestation of the politics of identity that is becoming increasingly common," he said. "Identity is sometimes about religion, sometimes about color, sometimes about nationality. And I think what is happening is that traditional left-right class alignments are becoming less and less relevant, and it's identity, in those different forms, that becomes salient," Cable added.

Anti-Semitism and Islamophobia

Religious identity has featured prominently in the run up to the election in the U.K. with both the main parties accused of failing to deal with religious discrimination and prejudice within their own ranks. In late November, the U.K.'s Chief Rabbi Ephraim Mirvis attacked the Labour party for failing to tackle anti-Semitism within its ranks, adding that the party's leader Jeremy Corbyn was "unfit for office." He also said in an interview with The Times newspaper that "the overwhelming majority of British Jews are gripped by anxiety" ahead of polling day as they fear a potential Labour government. Mirvis' comments came on the same day that Labour had launched a "race and faith manifesto," which it said aimed to tackle prejudice across all faiths. Labour has repeatedly denied accusations of anti-Semitism and has expelled party members after complaints of anti-Semitism were upheld yet it remains accused of not doing enough. The party came under fresh pressure this weekend when it emerged there was a backlog of unresolved complaints over anti-Jewish racism within the party, some dating back years. Shadow Finance Minister John McDonnell apologized to the Jewish community "for the suffering we have inflicted on them."

People hold banners during a protest, organized by Stand Up To Racism platform, against former British Foreign Secretary Boris Johnson after his Islamaphobic article, which includes hate crime on women those who wear niqab or burqa, in front of the contact office of Conservative Party in London, United Kingdom on August 09, 2018. Anadolu Agency | Anadolu Agency | Getty Images

While Labour's reputation has been tarnished in the Jewish community, the Conservative Party under Boris Johnson has been accused of not doing enough to tackle Islamophobia within the party. Johnson has come under fire himself for previous comments in which he likened Muslim women wearing burkas as looking "like letter boxes." On Sunday, Conservative Chairman James Cleverly apologized for cases of Islamophobia in his party and reiterated a promise made by Johnson that there would be an inquiry into prejudice and discrimination within the party by the end of the year. Like Labour, the Conservatives have expelled a number of party members for alleged Islamophobia. Cable, who once led the third-largest opposition party, the Liberal Democrats, said both the mainstream parties had upset ethnic minorities in the U.K. "The Labour party has got a very specific issue which relates to anti-Semitism ... they've got to clean up their act and I don't think they can do that as long as (Jeremy) Corbyn is their leader, frankly," he said. "The Tories are tapping into an underlying, often very racist feeling in parts of the country ... there is an undercurrent of hostility to ethnic minorities and Johnson has, through his language, has played into that, and I think they (the Tories) are a bigger problem than the Labour Party." Ben Ryan, head of research at Christian think tank Theos, told CNBC that the main problem with modern political parties in the U.K. was a failure to engage with faith groups on all sides, and tending to regard the issue of faith in negative terms. "There's been nothing really positive from the parties about how they're going to engage faith groups," he said. "There's been almost purely negative messaging about faith groups ... and a total absence from the debates of positive things faith groups can offer society. They're often pillars of social services in the community."

Don't mention God

Political parties might have trouble engaging with faith groups but they also have problems dealing with the religious identities of their own lawmakers at times. In fact, Vince Cable's predecessor Tim Farron, resigned from the leadership of the Liberal Democrats because he said he could not reconcile his faith, and remain "faithful to Christ" with being party leader. The difference between the U.S. and U.K. when it comes to religion and faith in politics is pronounced. In the U.S., former President George W. Bush was seen by the Christian right as a way to push a conservative Christian agenda while in the U.K., his then-counterpart Tony Blair (incidentally, both Bush and Blair were religious converts to a certain extent; Bush was born again as an evangelical Christian in 1985 and Blair who converted to Catholicism) was discouraged from expressing views on his personal faith. When announcing to the nation the start of the 2003 war in Iraq, Blair was apparently dissuaded by aides from ending his message with the phrase "God bless you" — a marked contrast from then-President George W. Bush who told the world that he was spurred to intervene in Iraq because, "God told me to end the tyranny in Iraq." Speaking to CNBC Wednesday, Tony Blair's former advisor Alistair Campbell said his "We don't do God" comment was a "totally off the cuff" remark to end an interview that Blair was doing at the time, but that it was resonant in a more secular country like Britain. "I'm an atheist and he (Tony Blair) wasn't and isn't, but I just think we're not like America. I feel American politicians feel they have to go to church, (say) "God bless America" and all that stuff and I just think here (in Britain) people just don't like it. They like politicians to be political," he said.