The country's latest, most severe outbreak has accounted for more than 80% of its total infections and 90% of deaths and it has yet to start mass COVID-19 vaccinations.

Southeast Asia's second-largest economy may grow 1.5%-2.5% this year, the state planning agency forecast earlier this month. The budget plan sees growth of 2.5%-3.5%.

"There are limitations and risks that could affect Thailand's economic recovery in 2021," Prime Minister Prayuth Chan-ocha told the House of Representatives, which plans to debate the first reading until Wednesday.

"There remains uncertainty over the situation of COVID-19 outbreaks at home and overseas that may be more severe and continue longer than expected," he said.

The 700 billion baht deficit is up from the 609 billion baht deficit for the current fiscal year.

The budget projects spending of 3.1 trillion baht ($99.23 billion), down about 5.7% this year. The gap comes from lower tax revenue, expected at of 2.4 trillion baht.

Opposition leader Sompong Amornvivat said the budget bill did not adequately address the coronavirus crisis.

"People are suffering from COVID-19 ... but I don't see any clear plans or strategies on how to handle that," he said.

The bill's second and third readings are expected in August.

The budget planners have assumed the economy will grow 4.0-5.0% in 2022.

($1 = 31.24 baht)

(Reporting by Panarat Thepgumpanat and Orathai Sriring; Editing by Martin Petty)