The Obama administration said on Tuesday that budget negotiators in Congress would probably fail to strike a far-reaching deal unless Republicans agree to raise revenues and overhaul the tax code. A 29-member congressional committee is trying to set spending levels for the fiscal year that began last month, and many lawmakers want to scrap large spending cuts that started in March. While President Barack Obama, a Democrat, is not officially a part of this process, his treasury secretary said the administration feels an overhaul of America's welfare state should not happen without rewriting tax laws and raising federal revenues. Republicans generally oppose any tax hikes.