The Congressional Budget Office (CBO) on Thursday released an analysis saying the $1 trillion bipartisan infrastructure package would add $256 billion to the federal deficit over the next decade, a difficult pill to swallow for GOP senators who have insisted on paying for the entire cost of the legislation.

The budget office estimates the bill would increase discretionary spending by $415 billion over 10 years while increasing revenues by $50 billion and decreasing direct spending by $110 billion.

“On net, the legislation would add $256 billion to projected deficits over that period,” CBO reported in its summary.

The bipartisan group of senators who negotiated the bill with the White House says it would spend $550 billion in new money over the current budget baseline. That means just more than half of the new spending — $294 billion — would be offset by pay-fors, according to CBO’s stringent standards for scoring legislation.