The candidates reflect the differences between Jewish groups living in Jerusalem, where in Orthodox neighbourhoods, families in traditional black garb attend the synagogue during the Sabbath and Jewish holidays while in downtown Jerusalem, secular Jews frequent non-Kosher bars and eateries.
"What people are voting on really is the soul and the character of the city," Jacky Rowland, Al Jazeera's Jerusalem correspondent, said.
"Under the outgoing mayor, who for five years has been running the city, we've seen an increasingly religious and increasingly strict social character in how the city is run - for example there is no public transport from sundown on Friday until the end of the Sabbath [Jewish weekly holiday]."
"The result is that many young people feel that Jerusalem doesn't have much to offer them."
Shmuel Sandler, a political scientist at Bar-Ilan University near Tel Aviv, said: "The culture war is the main issue. It's a battle between the secular and the ultra-Orthodox."
The Jerusalem vote is among the most significant of some 160 local elections being held across Israel ahead of a national parliamentary poll on February 10.
Though none of Jerusalem's mayoral candidates represent any of Israel's ruling parties, analysts warn there could be a backlash by voters against religious parties in the country-wide ballot if Porush wins.
Some 750,000 people live in Jerusalem, including 260,000 Palestinians. A candidate must poll at least 40 per cent or a second round of voting must be held.
A low turnout of secular voters could lead to a Porush victory, said analysts who attributed the 2003 win of Uri Lupolianski, the current Orthodox mayor, to the failure of many non-religious residents to vote.
"Please don't judge me by the length of my beard," Porush said during the campaign, but he has fuelled secular fears by saying he doubted there would be any non-Orthodox mayors in Israel in 10 years.
Barkat has angered some supporters by courting religious voters with promises to support Jewish settlement expansion in Jerusalem - a move Porush also supports.
Israel's Haaretz newspaper responded with an editorial urging "Vote 'no' on Barkat" and some intellectuals have vowed publicly not to vote for him.
Many secular Israelis in Jerusalem say they are worried by growing poverty in the city, where many ultra-Orthodox Jews have large families and low incomes.
There are also concerns over a growing "conservative" trend in Jerusalem.
City administrators caused a stir recently by forcing young women dancers at the ceremonial opening of a bridge to cover their hair and don sack-like dresses to avoid offending rabbis.