The ruling and opposition parties have agreed in principle to lower the bar for who should pay the highest income tax rate, sources said Sunday, in what would mark the first tax increase for the rich under the government of President Park Geun-hye.

Currently, those who make more than 300 million won ($285,000) a year are required to pay the highest income tax rate of 38 percent. But the rival parties have reached a consensus in the taxation subcommittee of the parliamentary finance committee that the bar should be lowered, the sources said.

The measure, if legislated, would mark the first tax hike for the rich since Park took office in February and would help reduce the shortage of state revenues needed for a series of expensive welfare and other programs Park promised during last year's election.

The rival parties have yet to work out the details, including by how much the threshold should be lowered. The liberal main opposition Democratic Party wants to apply the highest tax rate to those making more than 150 million won a year, while the ruling Saenuri Party wants to adjust the bar more moderately to 200 million won.

Sources also said that the minimum tax rate for conglomerates is expected to rise by 1 percentage point to 17 percent, an increase for the second year in a row after the rate rose by 2 percentage points at the end of last year. Conglomerates are expected to protest the proposed increase. (Yonhap News)