File: Former governor Robert F. McDonnell after his September conviction on public corruption charges. (Marvin Joseph/The Washington Post)

Former Virginia governor Robert F. McDonnell will be allowed to stay out of prison at least until the Supreme Court’s chief justice can consider his request for extended bail — a most modest victory for the disgraced politician as he tries to persuade the nation’s highest court to hear his case.

Chief Justice John G. Roberts Jr. on Monday ordered federal prosecutors to respond to McDonnell’s request for bail by 4 p.m. Wednesday, and put on hold the “mandate” in the case — a formal, final step that would initiate the process of sending McDonnell to prison.

The order, though, does not mean that McDonnell (R), who was convicted along with his wife of public corruption in September, will be allowed to remain out for months while he formally petitions the Supreme Court to take up his case. Rather, it means that he cannot be sent to prison until Roberts decides the immediate issue of whether he should be allowed to stay out on bail during that process — a matter that could be resolved in just days.

The distinction is important, as McDonnell still must overcome significant hurdles to win a true, lengthy reprieve.

A federal appeals court last week declined to allow the former governor to remain out on bail while he pursued a challenge with the Supreme Court and said its mandate would be issued Thursday.

Before Roberts’s order Monday, it was technically possible that the former governor could have been jailed at any time after that — although it was more likely, experts said, that the case would be sent back to a lower-court judge, who would set a date by which McDonnell had to report to prison.

Now, McDonnell knows that the Supreme Court will decide the issue of his bail — after considering prosecutors’ response — and a lower court will not order him to prison before then.

To win a longer reprieve, McDonnell must convince Roberts — or the full court, if Roberts decides that is necessary — that there is a “reasonable probability” that four justices would agree to review his case, that there is a “fair prospect” that a majority would ultimately rule in his favor and that he would suffer irreparable harm if his request were denied.

Doing that would be a significant win for McDonnell, giving him several months of continued freedom. The former governor has until Nov. 9 to file his petition with the Supreme Court, and the justices probably would take many weeks after that to consider whether they should hear the matter.

McDonnell’s wife, Maureen McDonnell, is pursuing her appeal separately and has been allowed to remain out of prison.