"There are enough signatures to hold the sitting," Viktoras Pranckietis, the speaker of the Seimas, told reporters on Monday.
There are two draft resolutions on the agenda.
One calls for assessing Prime Minister Saulius Skvernelis' role in deleting the recording of a government meeting where proposals on giving the media free access to registry data were discussed.
The draft resolution demands that Skvernelis should instruct his office to recover the deleted recording and make it available to the media and the general public.
The other draft resolution concerns the publication earlier this week by Ramūnas Karbauskis, leader of the ruling Lithuanian Farmers and Greens Union, and Agnė Širinskienė, chairwoman of the parliament's Committee on Legal Affairs, of a secretly recorded conversation between several members of the Chief Official Ethics Commission, or VTEK, and Mindaugas Siaurys, who was then head of the commission's Prevention Department.
The LVŽS MPs actions are denounced in the resolution as "blackmail against VTEK".
Karbauskis and Širinskienė are initiating impeachment proceedings against Povilas Urbšys, a former of the ruling, claiming that the secretly recorded conversation shows he might have ordered VTEK members to sack Siaurys.
Following the submission last Thursday of next year's draft budget to the Seimas, the parliament has adjourned for several weeks to discuss the bill in committees and political groups.
Under the Statute of the Seimas, an extraordinary sitting must be held when it is requested in writing by at least one-third of lawmakers or the Board of the Seimas.
Karbauskis has downplayed the opposition's initiative on the extraordinary sitting.
"It's a bubble, a blown-out bubble, as the prime minister has answered all questions. If the opposition wants to continue blowing that bubble, that's fine," he told journalists.