A Pheu Thai source said that the party had taken a decision to dissolve parliament, but was not aware of whether the required documents had been submitted to the relevant authorities.
The source asked not to be named because of the sensitivity of the matter.
Sorawong, the government spokesperson and the top aide to the acting prime minister, did not immediately respond to separate requests for confirmation from Reuters.
There are conflicting opinions among law experts in Thailand about whether a caretaker government has the authority to seek house dissolution.
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The move came as the People’s Party, which is the main opposition group that Pheu Thai and the Bhumjaithai party are looking to woo in a bid to form the next administration, said it had not made a decision on which camp to back.