Ever since the judge presiding over the AT&T Inc.- Time Warner Inc. merger case said he’d take the unusual step of reading his ruling aloud from the bench on June 12, investors, lawyers and journalists have eagerly anticipated this day. Seats in Judge Richard Leon’s courtroom are in such demand that lines began forming outside the E. Barrett Prettyman courthouse in downtown Washington a full day before the scheduled 4 p.m. announcement.

With less than five hours to go before the hearing begins, the line had moved inside the courthouse and snaked down the 6th floor hallway, complete with folding chairs. Peppered among the people eager to snare a seat were so-called line sitters, who are paid to hold spots — a practice common in Washington, and one that was used during the trial for big witnesses. The going rate is $36 an hour, meaning a front-row seat could run about $860.

Billions of dollars in the market could turn on the judge’s ruling, but people outside the courtroom won’t know what happened right away since Leon is likely to prohibit anyone from leaving until he’s done. Inside, the use of devices is verboten. The ban is so strict that guards have been known to demand to see mobile phones and laptops to make sure they’re turned off. Violators have been ejected. Leon has ordered a window into the courtroom to be covered so that no one outside the room can see when he takes the bench.

Usually, the public has instant access to merger rulings because they’re posted online rather than delivered orally in the courtroom. This time, Leon nixed a plan to set up an overflow room for reporters and others where live audio of his decision would be available. As a result, expect a race for the door once the hearing concludes.

Adding to the day’s drama — and to the crowd of news media and professional line-standers — a naturalization ceremony is taking place in the hallway of the courthouse, drawing eager family members of the soon-to-be U.S. citizens.

Oh, and the Washington Capitals are celebrating their Stanley Cup victory with a parade on Tuesday. It is set to conclude just blocks away shortly before Leon begins reading his decision.