Crimea will vote Sunday in a referendum that leaders of the regional Parliament expect will ratify their decision to break away from Ukraine and become part of Russia. The referendum will offer two choices, neither one of them “No”:

1) “Are you in favor of the reunification of Crimea with Russia as a part of the Russian Federation?”

2) “Are you in favor of restoring the 1992 Constitution and the status of Crimea as a part of Ukraine?”

Voters will have to mark one option affirmatively, but they cannot vote for the status quo.

A return to the 1992 Constitution — adopted after the Soviet collapse but quickly thrown out by the post-Soviet Ukraine — would effectively provide for Crimea’s independence, while remaining part of Ukraine. The Crimean government would have broad powers to chart its own course, including its relations with other nations such as Russia.

Retaining Crimea’s current status, which provides for more limited autonomy from the central government in Kiev, is not an option, which may help explain why the Crimean Tatars have refused to take part in the voting. No matter what voters choose, the regional Parliament seems intent on changing its relationship with Kiev. Meanwhile, Ukraine’s new leadership and its Western allies insist that the referendum is illegal.

The city of Stavropol, which has a special administrative status, will hold a simultaneous referendum offering the same choices.

As the vote approached, there has been an abrupt shift in civic life on the Crimean peninsula, where open dissent has been suppressed by the implicit threat of force. In a matter of days, the Russian government has succeeded in re-creating the constrained conditions of Russia’s own civic sphere in Crimea.

With a mix of targeted intimidation, an expansive military occupation by unmistakably elite Russian units and many of the trappings of the election-season carnivals that have long accompanied rigged ballots across the old Soviet world, Crimea has been swept almost instantaneously into the Russian government’s fold.

Barring an extraordinary surprise, the peninsula’s interim authorities, led by a previously unsuccessful politician nicknamed the Goblin, will announce that its citizens have voted to leave Ukraine and seek a place in President Vladimir Putin’s Russia.

To ensure an unchallenged realignment of territory and to project power to anyone who might resist, the organizers of secession have relied repeatedly on strong-arm tactics familiar to Putin’s opponents at home.

Organizers of counterprotests have been threatened and in some cases disappeared. Armed men in masks patrol strategic sites.

Crimean journalists have been ordered not to describe the soldiers on their soil as Russian or to use the word “occupation.” And foreign and local journalists have been beaten and had their materials confiscated by uniformed men who are not officially connected to any government.

Civilian-airline flights to and from Kiev, the Ukrainian capital, have been blocked. The Berkut riot police, disbanded in February under accusations of brutality by Ukraine, the state they once served, have regrouped in Crimea, where they stand as enforcers of the new authorities’ will.

All the while, Ukrainian government centers are blockaded by a mix of Russian troops and men identifying themselves as their supporters.

This has played out while thickets of signs declaring “Together with Russia” have sprouted along roadways, urging citizens to vote to leave Ukraine.

Whether this intensive social and political pressure is necessary is subject to debate.

Crimea, once part of Russia, has a strong historical and linguistic alignment with its Slavic neighbors to the east. A majority of its 2 million residents are ethnic Russians or Russian speakers and approve of rejoining the revived Russian state.

But the Russian government is taking no chances. On Monday, roughly 30 men in camouflage and carrying clubs pushed into Simferopol’s military hospital, walking the corridors and telling Ukrainian military officers there to leave.

The men stood in the hospital’s entrance for hours, checking documents of anyone who arrived. The hospital’s director, Lt. Col. Evgeny Pivovar, a Ukrainian army surgeon, said the men barred him from his own office. “They said, ‘You don’t work here anymore,’ ” he said.

While the intruders made no explicit threats, he said, it was not necessary. “Their presence here, it was understood,” he said.

After several hours, the men left, Pivovar said. But he does not know what will happen after the referendum Sunday. From that moment, Ukrainian military bases and buildings, like the hospital, could be declared Crimean property.

The colonel’s wife is from Crimea, and the couple has a young daughter. He said he expected that he would leave the peninsula for Ukraine. His family will likely stay behind. “I do not know what will be after the 16th,” he said.

Pro-Ukrainian activists have been flowing out of Crimea, frightened by an atmosphere of mounting aggression and growing indications the police will no longer protect them.

“The security services here have gone over completely to the side of the bandits,” said Sergei Makrenyuk, an organizer of the Crimean branch of the pro-revolutionary EuroMaidan group

Material from the Los Angeles Times is included in this report.