State media said the House of Representatives would convene a special session Friday to discuss the proposed measures outlined in an Oct. 1 letter. The contentious proposals include the power to restrict public gatherings and appropriate property "without payment of any kind or any further judicial process" to combat Ebola.
The letter also says Sirleaf can "limit the right to assembly for any reason."
Sirleaf's government imposed a three-month state of emergency beginning Aug. 6, and a statement warned at the time that this would involve suspending some rights and privileges.
The new proposals, however, drew protest as soon as they were read out in a plenary session earlier this month. A headline in the newspaper Women Voices this week asked: "Tyrannical Times or Ebola Preventive Measures."
"I see a kind of police state creeping in," said lawmaker Bhofal Chambers, a one-time supporter of Sirleaf who has since joined the opposition camp.
In August, a quarantine of the city's largest shantytown sparked unrest and was derided as counterproductive before being lifted. The Committee to Protect Journalists has accused Sirleaf's government of trying to silence media outlets criticizing its conduct.
On Thursday, Liberian police used batons and rattan whips to disperse 100 protesters speaking out against the proposed new powers. Student activist Benedict B. Williams urged lawmakers not to approve them.
"In my view I think the people have the right to assemble," Williams said. "This is tantamount to dictatorship. The police brutalized people who are from the student community."
Liberia has been hit hardest by the Ebola outbreak, recording more than 2,200 deaths, according to the World Health Organization. The total death toll as of Wednesday was 3,865.
Sirleaf's government announced Thursday that Senate elections scheduled for next week would need to be postponed. No new date was given.
Recent frustration with Sirleaf is not limited just to Ebola. Allegations of corruption and nepotism — especially the appointment of her sons to high-level posts — have been a fixture of her administration.
When Justice Minister Christiana Tah announced her resignation this week, she accused the president of blocking an investigation of the country's National Security Agency, which is headed by her son Fumba Sirleaf.
The president's office issued a statement saying only that she had accepted the resignation.
Six U.S. military planes and 100 Marines arrived in Liberia Thursday to help battle the Ebola outbreak.
Maj. Gen. Darryl A. Williams, the commander leading the U.S. response, and the American ambassador to Liberia, Deborah Malac, greeted the aircraft at the airport.
As vehicles unloaded boxes of equipment wrapped in green-and-black cloth, the Marines formed a line on the tarmac and had their temperatures checked by Liberian health workers. The U.S. military is working to build medical centres in Liberia and may send up to 4,000 soldiers to help with the Ebola crisis. Medical workers and beds for Ebola patients are sorely lacking.
Meanwhile, British authorities said they would introduce "enhanced" screening of travellers for Ebola at Heathrow and Gatwick airports and Eurostar rail terminals.
Prime Minister David Cameron's office said passengers arriving from West Africa would be questioned about their travels and contacts. Some people could be given a medical assessment and advice on what to do if they develop symptoms.
Elsewhere, University of Maryland researchers announced that the first study of a possible Ebola vaccine in Africa was underway. Scientists say three health care workers in Mali received the experimental shots developed by the U.S. government.
Mali has not had any cases of Ebola, but it borders the outbreak zone. Researchers say early safety tests should be done in Ebola-free countries to avoid complicating factors. If the vaccine appears to be safe, larger trials could be done in the outbreak zone early next year.
A Spanish hospital official says a nursing assistant infected with Ebola is "stable," hours after authorities described her condition as critical. A spokeswoman for the Carlos III hospital in Madrid said the patient, Teresa Romero, remained in serious condition Friday but could give no further details. Romero contracted the virus while helping treat a Spanish missionary who became infected in West Africa, and later died.
She is the first person known outside of West Africa to have caught the disease in the current outbreak.
Her brother, Jose Ramon Romero, told Spain's El Pais newspaper in an interview published Friday that he asked a doctor Thursday about the chances of his sister recovering.
The doctor "said that the situation is very complicated," Romero said.
Associated Press journalist Wade Williams contributed reporting from Monrovia.