Opposition leader R. Sambanthan said the no-confidence motion, which had been presented by an opposition party, gained majority support in a voice vote carried out in parliament, Reuters reported on Wednesday.
The news agency added that two other opposition lawmakers had confirmed the lawmakers’ approval of the motion.
The no-confidence motion against the new government leaves the already crisis-hit country in a power vacuum.
A political crisis started in Sri Lanka days ago when President Maithripala Sirisena abruptly sacked Prime Minister Ranil Wickremesinghe and his cabinet and suspended the parliament until November 16. He then appointed Rajapaksa as the new premier.
Sirisena sacked Wickremesinghe due to what he described as their inability to work with each other because of their deep personal and cultural differences.
Wickremesinghe warned that the move may ignite a conflict and lead to a “bloodbath” in the country. He also dismissed the president’s controversial decision to fire him.
The sacked prime minister argued that given his support in parliament, his ouster was illegal.
Sri Lanka’s Supreme Court on Tuesday ruled to suspend the president’s order to dissolve the parliament and hold new elections.