WASHINGTON -- The Senate is poised to permit the government to borrow hundreds of billions of dollars more to meet its obligations, putting off one Washington showdown even as others loom in coming weeks.

The measure would suspend the US$16.4 trillion limit on federal borrowing through May 18, allowing an estimated $450 billion in new debt to be added to the federal ledger.

The Republican-controlled House passed the legislation last week. A successful Senate vote would send the measure to President Barack Obama, who is expected to sign it into law immediately.

Without the bill, the government would default on its obligations by as early as mid-February.