Colombo, October 30: Angry protests rocked Sri Lanka's capital as thousands of demonstrators gathered on Tuesday for a mass rally organised by ousted prime minister Ranil Wickremesinghe's party against what it said was a "coup" by President Maithripala Sirisena, even as the opposing sides were engaged in efforts to secure their numbers in Parliament to end the country's political crisis.

"Sirisena has broken his promise and taken executive powers into his hands. He has sidelined parliamentary power," UNP leader Wickremesinghe said, addressing the crowd.

Wickremesinghe's United National Party (UNP) demanded that Parliament be convened immediately and democracy restored. The ousted premier alleged that President Maithripala Sirisena had assumed he would get his way. Sacked Sri Lanka PM Ranil Wickremesinghe Seeks Emergency Session of Parliament.

However, he said the UNP and its partners in the United National Front will not give up and will continue to push for Parliament to convene immediately.

The UNP claimed about 100,000 people thronged the rally, though police sources estimated the number at 25,000.

Sri Lanka, a Buddhist-majority nation in the Indian Ocean, was plunged into chaos on Friday when Sirisena sacked Wickremesinghe as prime minister in a surprise move. He also suspended Parliament in an apparent bid to shore up support for newly-appointed Prime Minister Mahinda Rajapaksa.

Sirisena is under increasing political and diplomatic pressure to reconvene Parliament and resolve the Constitutional crisis. Wickremesinghe's United National Party (UNP) is set to hold a protest on Tuesday in the capital, Colombo.

Earlier, ahead of the rally, Champika Ranawaka, a former minister said, "We are calling upon all sections of the society who believe in democracy and rule of law to gather and protest".

Mangala Samaraweera, the ex-finance minister under Wickremesinghe said, "This was a Constitutional coup and it is our duty to protect democracy and sovereignty of people".

Speaker Karu Jayasuriya urged the president to let Wickremesinghe prove his majority support on the Parliament floor. The supporters of Rajapaksa, a former president, are confident that he would be able to prove majority support in Parliament as they are sure that members of Wickremesinghe's UNP would defect. "We are waiting for more UNP members to join us. We have the numbers," Lakshman Yapa Abeywardena, a Rajapaksa loyalist, said.

Wickremesinghe has said that he still commands a majority. However, he suffered a setback after four lawmakers from his party, who had pledged allegiance to him in public, took a U-turn and accepted ministerial positions in the Rajapaksa government. "We have the majority despite four of them joining Rajapaksa," Ranjith Madduma Bandara, an ex-minister, said.

Speaker Jayasuriya has called for a meeting of all party leaders to assess the current political situation. At least 128 members had written to him calling for reconvening of Parliament.

Jayasuriya has insisted that the issue needs to be settled within Parliament.

Both Wickremesinghe and Rajapaksa are working to secure their numbers in parliament.

The leaders of the main Tamil party, Tamil National Alliance (TNA), met Rajapaksa this morning to discuss the current political situation. TNA sources said R Sampanthan, who is also the leader of the main Opposition, was asked by Rajapaska to stay neutral in case of a floor test.

The TNA has 16 MPs in the 225-member assembly and can play a crucial role in deciding the legitimacy of the government. Rajapaksa needs 18 more MPs to give him a simple majority of 113 in the House of 225 members.

Rajapaksa's tenure as president was marred by allegations of authoritarianism, corruption and human rights abuses, especially against the country's Tamil minority. He was defeated in the 2015 presidential election when Wickremesinghe and Sirisena formed an unlikely coalition, and their government initiated several investigations into alleged Rajapaksa-era crimes.

Under Sri Lanka's Constitution, the president, who maintains executive powers, can appoint a new prime minister once the current premier has lost control of Parliament.

Wickremesinghe argues he cannot legally be dismissed until he loses the support of Parliament. His party was prevented from holding a vote when Sirisena abruptly suspended Parliament on Saturday until November 16.

Wickremesinghe claimed in a Facebook post on Monday that he had obtained the signatures of 126 MPs calling for Parliament to be reconvened immediately to end the political standoff.