President Barack Obama made an eleventh-hour appeal to Congress Wednesday morning to pass the $858 billion tax cut package “as swiftly as possible” when it comes up for a vote in the Senate later in the day and in the House later this week.

The tax proposal, which the White House negotiated with Senate GOP leaders, must not “fall victim to either delay or defeat,” Obama said during brief remarks at the White House.

The president acknowledged that lawmakers in both parties are unhappy with certain aspects of the measure, which extends Bush-era tax cuts for two years, but he said people have “worked hard to negotiate an agreement” that can pass.

“I am absolutely convinced” the package will boost the economy and create jobs, he said.