George Papadopoulos is supposed to start his two-week prison sentence next week, but his lawyers are requesting a two-week delay pending the outcome of a separate case challenging the constitutionality of special counsel Robert Mueller’s appointment.

Papadopoulos, 31, was on President Trump’s foreign policy advisory team during the 2016 presidential election, and subsequently became part of Mueller’s investigation into Russian election interference and possible collusion with the Trump campaign.