Washington (CNN) Republican Sen. Rand Paul said Thursday he was effectively blocking a vote on a spending bill ahead of a government shutdown deadline at midnight to put lawmakers on the spot over the national debt.

"I can't in all good honesty, in all good faith, just look the other way because my party is now complicit in the deficits," Paul said on the Senate floor.

The Senate was set to consider the spending agreement announced by Senate Majority Leader Mitch McConnell and Minority Leader Chuck Schumer, but an attempt by Paul to include his own amendment appeared to hold up a vote as of Thursday evening.

Paul said he objected to the deal to lift budget caps over the next two years, which, alongside the GOP's tax cuts passed late last year, will add further to the deficit, and blasted the process around the debate itself.

"This is the most important debate we will have in the year over spending, and no amendments are allowed," Paul said.

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