The two men hoping to succeed longtime German Chancellor Angela Merkel meet their respective parties on Monday, in the hope of gathering vital support ahead of national elections in September.
The two politicians, Armin Laschet and Markus Soeder, are both leaders of parties in Germany's governing conservative bloc, which traditionally chooses only one person to be its candidate for chancellor.
Laschet, from Merkel's Christian Democrats (CDU), is meeting his party leaders this morning, apparently confident that a majority will back him against Soeder. "That is what I am assuming," he said in a live media event late on Sunday evening.
Soeder, from the CDU's Bavarian sister party, the Christian Social Union (CSU), is meeting his party this afternoon to seek its support.
While enjoying greater popularity in national opinion polls, Soeder will also have to convince the CDU - the much larger of the two parties - that he's the best person for the job, although he is not a CDU member himself.
Despite the now open competition between the two - who officially declared their intention to run on Sunday after months of speculation - Laschet and Soeder are insisting they will help maintain unity and cooperation within the conservative bloc.
A decision could come this week or in the next 10 days "at the latest," Soeder told reporters on Sunday.
Whoever wins the right to be the CDU/CSU's candidate will still be long way from the chancellor's office. They would need to lead their parties to victory in the elections on September 26, and after that most likely find one or two coalition partners to form a government.