As Mueller faces the task of resolving that piece of his inquiry — as well as his examination of whether President Trump has sought to obstruct the probe — people familiar with the investigation said the special counsel is pushing to wrap up a significant portion of his investigative work by the end of summer.

There are various factors that could alter Mueller’s efforts and timeline, most notably whether the standoff over an interview with Trump is resolved or ends up being litigated in court, according to the people, who spoke on the condition of anonymity to be able to discuss an ongoing investigation.

As recently as this week, Mueller’s team has discussed interviewing more witnesses, a sign that a part of the probe remains very active, a person familiar with the matter said.