CAIRO — President Mohamed Morsi of Egypt moved aggressively on Thursday to preserve order and confront his opponents, deploying the army near government ministries and the Suez Canal, starting legal proceedings against several judges and purging critics from a state-appointed body that helps regulate the airwaves.

While many had hoped that Mr. Morsi would move to defuse calls for mass protests against him this weekend, he instead wielded the power of the state to project power. His message to those challenging his authority was to either work through the political structures that have emerged since the country’s revolution in 2011, or have no say in how the state is run.

“One year is enough!” Mr. Morsi said repeatedly in a televised speech on Wednesday night, threatening to purge holdovers from the clique of former President Hosni Mubarak. He also offered no major concessions to those calling for his ouster, dismissing them as antidemocratic.

“This is the message he is sending, a threat pretty much that his tolerance and patience for so-called subversive acts and extra-constitutional activities will no longer stand,” said Yasser el-Shimy, an analyst with the International Crisis Group. “If you would rather work outside the system, we are going to come after you.”