This is due to the fact that there are more members in the opposition than in the government.
In the Parliament chamber, 116 seats have been allowed each for the government and opposition MP.
However, at the present, there are only 96 government MPs while there are 128 opposition members in addition to the Speaker.
Therefore, 12 opposition MPs will be compelled to sit in the government benches.
Speaking, Parliament Sargeant-at-Arms Narendra Fernando said that 12 UNP MPs will be taking up seats where the government backbenchers usually sit.