Zia, chief of the Bangladesh Nationlist Party (BNP), called on her arch rival Prime Minister Sheikh Hasina to hold an immediate dialogue on a fresh election under a non-party regime.
"Let's hold an election under a non-party government to bring peace to the country," she told about 35,000 of her supporters during her first rally in Dhaka after a virtual house arrest was eased.
The people would accept the results from such polls, she said. She called on the Awami League government to create a congenial atmosphere for an acceptable election through dialogue, The Daily Star reported.
The two-time former premier said: "This government is illegal. Hold polls very quickly and test your popularity...The government does not have public support.
"It is trying to stay in power by using force. But no government can stay in power this way for long."
The BNP-led 18-party opposition alliance boycotted the January 5 polls which were marred by deadly violence and a low turnout. The Awami League swept the polls, winning many seats uncontested.
She was prevented from addressing rallies as the government feared it could lead to unrest before the polls. Authorities have officially denied that Zia was ever under house arrest.
During her speech, Zia accused the ruling party for recent attacks on Hindus. "The government has to bear all responsibilities because it has failed to protect them and arrest the attackers."
She alleged the government was creating new issues to distract people from pressing matters.
This was Zia's second public address since October 25 last year, when she issued a 48-hour ultimatum to Hasina to meet the opposition's demand for holding polls under a non-party caretaker government.
In the run up to the polls, the opposition staged violent strikes and transport blockades in a failed attempt to derail the vote. The violence left around 200 people dead.
