(Recasts with Senate delay on passage)
By Richard Cowan
WASHINGTON, March 22 (Reuters) - Legislation to fund the government beyond Friday, which was on a fast track toward passage by the U.S. Congress, hit a bump on Thursday as Republican Senator Rand Paul employed procedural delays while he hunkered down to read the 2,232-page tome.
Earlier on Thursday, Republican leaders rushed the $1.3 trillion bill, which would fund the government until Oct. 1, through the House of Representatives. Passage there kicked the action over to the Senate.
Lawmakers were racing against a midnight Friday deadline, when current federal funding expires, in hope of avoiding a third partial government shutdown this year.
While Paul so far was alone among 100 senators in acting on his objections to the legislation, conservative Republicans in both house of Congress were fuming over it.
In a series of tweets, Paul, a small-government conservative and opthalmologist by training, complained his office printer was laboring for hours to produce a hard copy of the legislation.
Paul has imposed his will, or at least his delays, on the Senate during several past legislative battles as well.
"Shame, shame. A pox on both Houses - and parties. Here’s the 2,232 page, $1.3 trillion, budget-busting Omnibus spending bill," Paul declared in one tweet.
He decried a "wasteful" $6 billion for the National Science Foundation and a "monstrous bill" teeming with decades-old grant programs.
Earlier in the day, an optimistic Republican Senator John Cornyn, a member of the Senate's leadership team, said passage of the bill could come on Thursday night.
Without Paul's cooperation, the Senate might not be able to cast its first procedural vote until 1 a.m. on Saturday, which would technically force U.S. government agencies into shutdown mode.
Some senators still held out hope that Paul would relent sometime before Saturday and allow a vote so that Republicans do not suffer the embarrassment of presiding over another shutdown.
The legislation has some appealing provisions to conservatives with its $80 billion increase this year to the military budget and more border security funding.
But significantly higher non-defense spending put conservatives on edge. In the House, 90 of the chamber's 238 Republicans revolted against the bill that passed on a vote of 256-167.
Coupled with recently enacted tax cuts, the bill to fund the government through Sept. 30 is projected to lead to budget deficits of more than $800 billion for this year. Conservatives warned it could create problems for Republicans running for re-election in November.
"This omnibus doesn’t just forget the promises we made to voters - it flatly rejects them," Representative Mark Meadows, head of the conservative House Freedom Caucus, said after the vote. "This is wrong. This is not the limited government conservatism our voters demand."
President Donald Trump, who has submitted budgets to Congress aimed at taking a hatchet to many federal agencies, nonetheless would sign the bill, the White House said.
SCALED-BACK TRUMP PROPOSALS
Trump initiatives would suffer several setbacks, including his drive, at one point during prolonged negotiations, for $25 billion in funds to build his border wall with Mexico.
The president's severe cuts to the Environmental Protection Agency, State Department and other federal agencies would also be scaled back.
Democrats complained that in the rush to pass the bill, few if any lawmakers had time to read through the gigantic bill to see what it actually contained. The bill was unveiled late on Wednesday.
White House budget director Mick Mulvaney told reporters the legislation "does a lot of what we wanted – not everything we wanted – but a lot of what we wanted on immigration."
Trump said on Twitter the bill would allow him to start building the wall, which he calls an essential part of efforts to reduce illegal immigration. "Got $1.6 Billion to start Wall on Southern Border, rest will be forthcoming," he wrote.
But Democrats, who have long opposed the wall, argued the added funds would help build or restore a range of other barriers, including existing fencing, but not a concrete edifice.
Trump's original assertion that Mexico would finance the wall has been met with solid resistance by the Mexican government.
The $1.6 billion would also be used to hire more border patrol agents. But there would not be a significant increase in immigration agents working in the interior of the country, or in detention beds needed to increase immigrant deportations.
The Department of Homeland Security had sought a big buildup in those officers to boost deportation of immigrants in the country illegally.
Besides the largest defense buildup in 15 years, the measure includes new money for improvements to the country's infrastructure, and to counter Russian election hacking.
In response to public anger and frustration over mass shootings, including a Feb. 14 massacre at a Florida high school, the bill also contains modest improvements to background checks for gun sales and grants to help schools prevent gun violence.
Those provisions were far short of steps many Democrats and gun control groups say are needed to prevent repeats of mass killings of school children, concertgoers, church worshipers and others.
Additional reporting by Amanda Becker and Susan Heavey; Writing by John Whitesides; Editing by Frances Kerry and Peter Cooney