How much of a big deal is London's mayoral election?

Londoners head to the polls on Thursday to elect their third mayor, likely picking Sadiq Khan, who would be the first Muslim mayor of any major European city.

Voters in London go to the polls Thursday to elect their third mayor, likely choosing between representatives of the two major parties: Sadiq Khan of Labour and Zac Goldsmith of the Conservatives.

The flamboyant and charismatic incumbent, Boris Johnson, is expected to be replaced by Mr. Khan, which would give the British capital its first Muslim mayor – in fact, the first Muslim mayor of any major European city.

Race and religion have already played a bleak role in this contest, and while the outcome could have international implications, perhaps the most pertinent aspect of the campaign is its reflection of the turmoil currently plaguing British politics, the blurring of lines between traditional party battlegrounds.

"It's a fantastic tale of two Londons,” says Richard Whitman of Chatham House, a London-based international affairs think tank, in a telephone interview with The Christian Science Monitor. "It's absolutely ridden with issues of class, which is the British obsession."

Indeed, at first glance, the two leading candidates (there are 12 in total) offer starkly different choices. Khan, a former human rights lawyer and government minister, is the son of a Pakistani immigrant bus driver; Mr. Goldsmith is a prominent environmental campaigner and the son of a billionaire businessman.

Moreover, the parties they represent traditionally stand for very different policies, in tune with quite specific parts of British society. Labour has long been regarded the working man's party, concerned with social issues, while the Conservatives are seen as more aligned with business and the wealthy.

But some analysts perceive the crumbling of these party lines, and in many ways both mayoral candidates have found themselves standing apart.

Goldsmith has been trying to "steal the other party's clothes," talking about issues such as public housing, and being confronted with "issues of race and identity," says Dr. Whitman, who is also a professor of Politics and International Relations at the University of Kent.

"Throughout the campaign, Mr. Goldsmith has done one thing: attacked his Labour opponent Sadiq Khan for sharing a platform with extremists (despite having done the same thing)," wrote Sebastian Payne in the Financial Times. "As the conservative commentator Peter Oborne has argued, Mr. Goldsmith has imported Donald Trump’s incendiary language to Britain."

But Khan, too, has been at odds with his party's current leadership, as Tim Knox of the Centre for Policy Studies, a London-based center-right think tank, explains:

"Sadiq Khan has been careful to distance himself from Jeremy Corbyn [Labour's leader] in terms of this election, so a win wouldn't be an endorsement of the far left," Mr. Knox tells the Monitor in a phone interview. "He has been much quicker to come out against antisemitism than Corbyn."

Labour's current leader, Jeremy Corbyn, has pulled his party further left than it has stood for decades, making it, in the eyes of some analysts, unelectable.

But more immediate to Khan's campaign were recent comments made by London's first mayor and fellow Labour party member, Ken Livingstone, suggesting that Adolf Hitler had been a supporter of Zionism.

Mr. Livingstone has since been suspended and an independent inquiry launched into antisemitism within the Labour Party, but some observers wonder at the length of time it took for the Labour leadership to take action.

The mayoral campaign, therefore, has become swamped by such issues and does not appear to represent a straightforward contest between entrenched ideologies. Rather, as Knox of the Centre for Policy Studies puts it, it is "much more of a personality contest and party loyalty contest than based on significant policy."

There are some who see the issues being debated in this campaign – and the unorthodox stances adopted by Goldsmith and Khan – as symptomatic of a deeper shift, a trend that could forever change the face of UK politics.

"Nowhere encapsulates the growing gulf between the traditional left-right spectrum and the reality of modern Britain better than London," notes The Economist. "The old ideological battles are giving way to struggles over specific ethnic and religious groups."

In time, the political landscape may have to adapt, in spite of its institutional conservatism.

For now, though, as voters head to the ballot box on May 5, London looks set to be led by a Muslim mayor. The future that heralds remains murky, but there is the potential for an impact on relations with the Muslim world, both domestically and internationally.

"It's absolutely fascinating, but unknowable," says Whitman of Chatham House. "Will Khan focus on the harmonious cosmopolitan nature of London? Will he play to the rest of the Muslim world to the benefit of London?"