He belongs to the left wing of the party.
A left-wing politician proposed a new social policy.
The left wing of that party opposes the reforms.
In recent years, the left wing has been gaining influence within the party.
右派 is the political right wing, directly opposite 左派, the political left wing.
Compound of 左 (left) and 派 (faction, group). The political sense follows the seating arrangement in the French National Assembly after the Revolution, where radicals sat on the left.