WASHINGTON (AP) — Democrats controlling the Senate plan to move quickly toward a vote to allow the government to borrow more money, challenging Republicans to a filibuster showdown as the time remaining to stop a first-ever default on U.S. obligations ticks by.

A spokesman said Senate Majority Leader Harry Reid could unveil the measure as early as Tuesday, setting the table for a test vote later in the week. The measure is expected to provide enough borrowing room to last beyond next year's election, which means it likely will permit $1 trillion or more in new borrowing above the current $16.7 trillion debt ceiling that the administration says will be hit on Oct. 17. It's not expected to include new spending cuts sought by Republicans.

The development comes as a partial shutdown of the government enters its second week with no end in sight.