Germany's Christian Democrats (CDU) will take a step towards replacing Angela Merkel as leader of Europe's biggest economy in a vote on Friday that could push the party along a more pronounced conservative path.

Two candidates out of a field of 12 have emerged as frontrunners to take over from Merkel as the new party chief when 1001 CDU delegates vote at a party conference in the northern German city of Hamburg. But the race for the party's top post between CDU secretary general Annegret Kramp-Karrenbauer and Friedrich Merz, a businessman and former CDU heavyweight, also represents a battle over the future direction of the party.

After 18 years with Merkel as CDU chief and 13 years as chancellor, sections of the party are now keen to make a break with Merkel's pragmatic and centrist era. The nation's ambitious Health Minister Jen Spahn, a major critic of Merkel from the party's right wing, is also a contender.

As a result, analysts see Friday's vote as likely to push the CDU in a more conservative direction, which could also have wider ramification for the balance of power in Europe and regional alliances.

"All of the main candidates are more conservative and traditional than Merkel," Thorsten Faas, political scientist at Berlin's Free University, told dpa. "But the degree to which this will take place depends on who wins," Faas said. "Spahn and Merz are more conservative than Kramp-Karrenbauer."

Merkel announced in October that she would give up the CDU leadership at this week's party convention and would not seek re-election in 2021, saying that she hoped her decision would "open the way into the future." As a result, success in Friday's ballot would likely represent the victor's first step to becoming the next chancellor. The CDU and its Bavarian-based Christian Social Union (CSU) allies remain the nation's major political force, despite a recent series of setbacks and crises.