The parliamentary majority of Sri Lanka's ruling coalition headed by President Gotabaya Rajapaksa has come under threat with dissident lawmakers, led by former president Maithripala Sirisena, planning to break away from the government against the backdrop of nationwide protests over the country's worst economic crisis.

Sri Lanka is currently experiencing its worst economic crisis in history. With long lines for fuel, cooking gas, essentials in short supply and long hours of power cuts, the public has been suffering for months.

The 225-member Parliament will convene on Tuesday in its first session since a state of emergency was declared by President Rajapaksa last week.

The dissidents, led by former president Sirisena's Sri Lanka Freedom Party (SLFP), would leave the ruling Sri Lanka Podujana Peramuna (SLPP) coalition with its 14 Members of Parliament, party sources said after their meeting with the President on Monday.

The coalition, which commanded 157 votes out of 225 at the last vote held on the government budget, is bound to lose between 50-60 members, Udaya Gammanpila, a dissident lawmaker told reporters on Monday.

As a result, the government would not only be denied its two-thirds but even the simple majority of 113 members, he said.

However, Rohitha Abeygunawardena, a SLPP lawmaker, said that the government was rock solid with 138 members backing it.

The dissidents said that in addition to 14 members of Sirisena, 16 more from the other 11 members of the coalition would defect to be an independent group. They expect at least 20 from the SLPP to join their ranks.

On Monday, there were storming of houses of many government politicians, including Prime Minister Mahinda Rajapaksa's country house deep southern province, by angry demonstrators.

Prasanna Ranatunga, who is a fierce Rajapaksa loyalist, said, President won't resign due to protests, but he is willing to hand over the government to anyone who could prove 113 .

The President on Monday fired his brother and Finance Minister Basil Rajapaksa from his post and invited the Opposition parties to join a unity Cabinet to tackle the raging public anger against the hardships caused by the economic crisis.

Opposition parties have rejected the offer.

The President, who named just four members to his new Cabinet, would be forced to appoint his own SLPP Cabinet on Tuesday, analysts said.

Despite the declaration of the state of emergency and a weekend curfew, people joined the protests calling for the resignation of Rajapaksa.

It appeared that Rajapaksa's unity Cabinet plea had no resonance with the public as they were out in larger numbers, calling for the resignation of the entire Rajapaksa family from politics.

Following the 2019 Sri Lankan elections, the Rajapaksa family has kept several portfolios in the current government under their control.

While President Rajapaksa holds the all-powerful executive presidency, his elder brother Mahinda, who is a former president, is the current prime minister.

Basil held the finance ministry portfolio until his sacking on Monday.

Mahinda's son Namal, the heir apparent, is the minister of youth and sports.

India recently announced to extend a USD 1 billion line of credit to Sri Lanka as part of its financial assistance to the country to deal with the economic crisis following a previous USD 500 billion line of credit in February to help it purchase petroleum products.

During his recently-concluded visit to Colombo, External Affairs Minister S Jaishankar had assured India's continued support in Sri Lanka's economic recovery process.

President Rajapaksa has defended his government's actions, saying the foreign exchange crisis was not his making and the economic downturn was largely pandemic driven with the island nation's tourism revenue and inward remittances waning.