The statement said the prime minister had shown respect for the people who elected Pheu Thai to form the government through clean and fair elections.
It said political rallies are acceptable as long as they are peaceful and conducted without weapons, but argued the protest led by Suthep Thaugsuban of the People's Democratic Reform Committee (PDRC) and other groups is not.
"The prime minister decided to dissolve the House to avoid loss of life and injuries, as happened in the past. She has made the right decision and we hope the Thai people understand," the statement said.
Pheu Thai urged Mr Suthep and his supporters to call off the protest, return occupied government offices to officials so they could do their jobs, and free up roads for public use.
The statement also called on the Democrats and other parties to take part in the coming general election by campaigning and announcing policies to allow people to decide who to vote for.