WASHINGTON — The Internal Revenue Service is about to pay $70 million in employee bonuses despite an Obama administration directive to cancel discretionary bonuses because of automatic spending cuts enacted this year, according to a GOP senator.

Sen. Chuck Grassley of Iowa says his office has learned that the IRS is executing an agreement with the employees’ union today to pay the bonuses. Grassley says the bonuses should be canceled under an April directive from the White House budget office.

The directive was written by Danny Werfel, a former budget official who has since been appointed acting IRS commissioner.

“The IRS always claims to be short on resources,” Grassley said. “But it appears to have $70 million for union bonuses. And it appears to be making an extra effort to give the bonuses despite opportunities to renegotiate with the union and federal instruction to cease discretionary bonuses during sequestration.”

The IRS said it is negotiating with the union over the matter but did not dispute Grassley’s claim that the bonuses are imminent.

“IRS is under a legal obligation to comply with its collective bargaining agreement, which specifies the terms by which awards are paid to bargaining-unit employees,” IRS spokeswoman Michelle Eldridge said.

The IRS has been under fire since last month, when IRS officials acknowledged that agents had improperly targeted conservative groups for additional scrutiny when they applied for tax-exempt status during the 2010 and 2012 elections. A few weeks later, the agency’s inspector general issued a report documenting lavish employee conferences during the same time period.