Reul was a CDU delegate to the Federal Convention for the purpose of electing the President of Germany in 1994, 1999, 2004, 2009, 2010 and 2017. Since 2012, he has been serving on the Presidium of the CDU, under the leadership of successive chairwomen Angela Merkel (2012-2018) and Annegret Kramp-Karrenbauer (since 2018). In the negotiations to form a "Grand Coalition" of Merkel's Christian Democrats (CDU) together with the Bavarian CSU) and the Social Democrats (SPD) following the 2013 German elections, he led the CDU/CSU delegation in the working group on banking regulation and the Eurozone; his co-chair from the SPD was Martin Schulz.