Entering the final stretch of an arduous process, the Republican-controlled Senate began voting Monday on amendments to President Donald Trump's massive tax cut and spending bill, with the goal of passing it later in the day.

The $3.3 trillion legislation survived a brief GOP revolt over the weekend to allow the Senate to move forward with debate on the measure, but its final passage is far from certain.

Senate Republicans can afford to lose no more than three of their own votes on the bill, but two already are opposed and others remained undecided.