The GOP-led Senate is plowing ahead on a $612 billion defense policy bill despite Democratic opposition and a White House veto threat.

Sen. John McCain, the Senate Armed Services Committee chairman, says he expects at least 100 to 200 amendments to be introduced.

Debate started Wednesday.

The White House takes issue with several items. Topping the list is a move to put billions of dollars of defense spending into an emergency war-fighting fund, which isn't subject to congressional spending limits imposed in 2011.

Republicans say that because of those caps, this is the only way to authorize enough money defend the country.

President Barack Obama says he will not support a budget that locks in the spending caps.