Senate Minority Leader Chuck Schumer said Wednesday Senate GOP "do not have the votes" to pass a pending funding bill, setting up a potential showdown over government funding with just days to go before a shutdown deadline.

The Senate is now considering a continuing resolution that would fund the government for six more months, but some Democratic senators have pushed back on the bill, preferring to see more checks on executive branch power or a shorter-term bill that would give them time to build a new agreement.

Schumer said Wednesday that because Democrats in Congress didn't have input on the funding bill, they would oppose passage of the legislation as it stands.

"Our caucus is unified on a clean April 11 CR that will keep the government open and give Congress time to negotiate bipartisan legislation that can pass," Schumer said. "I hope our Republican colleagues will join us to avoid a shutdown on Friday."

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The bill proposes to fund the government through the end of September and largely maintain funding levels from last year. Non-defense spending would decline by some $13 billion compared to last year, and defense spending would increase by about $6 billion.

The House approved the bill 217-213 Tuesday. But Republicans hold 53 seats in the Senate, short of the 60 votes required to avoid a possible filibuster against legislation.

If the bill is not passed in the Senate, the government will face a shutdown starting on Friday.