Backers of the Central America Free Trade Agreement (CAFTA), a small yet pivotal trade pact with wide implications for the administration’s free-trade agenda, are preparing for what could be a bruising battle to pass it in the House.

As the House comes into session today, CAFTA supporters, who include many business and agriculture groups and most House Republicans, kick off a monthlong sprint to bring the agreement to a floor vote before the July 4 recess. Should they fail, it would lend ammunition to an already strong opposition consisting of labor unions, the sugar industry and most House Democrats.

CAFTA proponents already face a daunting legislative calculus. Rep. Sherrod Brown (D-Ohio), who has been leading House opposition to the pact, said before last week’s congressional recess that he had amassed 40 to 50 Republicans and 190 Democrats to vote against the measure, well ahead of the 218 votes needed to sink it.

Pro-CAFTA lobbyists said those numbers are inflated but nonetheless conceded that they face an uphill battle to muster support for the agreement in such a short time frame.

“I think it’s going to be real tough to do it that quickly. All the ducks would have to be perfectly in a row for that to happen,” one lobbyist said, noting that it was likely a vote would spill over into July. The lobbyist disputed Brown’s claim of Republican opposition, saying at most 30 were opposed.

A recent survey by Washington Trade Daily of 343 House offices found that 32 Republicans, 158 Democrats and one independent said they “will or are likely to vote against CAFTA.” Over 70 members were undecided.

In an effort to chip away at those numbers, business groups coordinated lobbying campaigns in members’ districts during the congressional recess. Yet Brown contended that such grassroots lobbying had failed to pull any members across the fence.

“It’s when people come back to Washington and the president starts beating them up, bringing them to the White House and offering them deals, that the numbers start to drop, even then they don’t drop enough” to allow the pact to pass, Brown said.

The administration hopes to prove him wrong. Administration officials have been active lobbying the Hill in recent weeks. U.S. Trade Representative Rob Portman, Secretary of State Condoleezza Rice, her deputy Robert Zoellick, Defense Secretary Donald Rumsfeld, Commerce Secretary Carlos Gutierrez and National Security Adviser Stephen Hadley have all made calls or visits to the Hill. President Bush has made passage of CAFTA a familiar refrain in his speeches.

Both sides are drawing parallels between the CAFTA vote and the 2002 House vote on trade-promotion authority, which gave the administration expanded powers to negotiate trade deals. Sizable Democratic support in 2002 — 25 Democrats crossed the aisle — helped Republican leaders overcome dissension in their own ranks about the free-trade agenda. The CAFTA lobby is hoping for the same scenario this time, while anti-CAFTA forces are hoping to thwart it.

“We know we’re going to lose a certain number of Republicans. We need Democrats to make up for that. This vote ain’t happening without Democrats,” said a senior House GOP leadership aide.

Yet Brown was confident he could keep Democrats lined up against the deal.

“Our whip operation is going to step up another notch,” he said.

Four Democrats have declared their support for CAFTA: Reps. Henry Cuellar (Texas), Norm Dicks (Wash.), William Jefferson (La.) and Jim Moran (Va.).

Lobbying groups plan to target the Congressional Hispanic Caucus (CHC) this week. After a meeting at the White House with Portman, members of the Hispanic Alliance for Free Trade, a relatively new group lobbying for CAFTA, will visit at least thirty House offices Thursday, said Anne Alonzo, a lobbyist with the National Free Trade Council, which is a member of the alliance. Of the 21 members of the CHC, 14 have publicly declared their opposition. One, Cuellar, is in favor.

Alonzo said the Hispanic Alliance is targeting members with high Hispanic populations in their districts.

Several sources working to pass CAFTA said they held hopes that Rep. Charlie Rangel (D-N.Y.), ranking member on the Ways and Means Committee, would vote for the measure during its expected committee consideration next week. Rangel has a sizable Dominican population in his Harlem district and has long enjoyed strong ties with the Dominican Republic.

Rangel, however, recently issued a statement saying that he “strongly supports the right free-trade agreement with Central America and the Dominican Republic” but that the current agreement lacks “even the most basic standards of common decency and fairness for working people.”

Even without Rangel, CAFTA is likely to sail through the committee with the support of Republicans and Jefferson. Rep. John Tanner (D-Tenn.), one of the 25 Democrats to vote yes on trade-promotion authority, is also reportedly in play.

A mock mark-up of the trade pact is tentatively scheduled for next week.

CAFTA supporters were also optimistic that several members from districts in the Carolinas with strong textile interests, such as Rep. Howard Coble (R-N.C.), would be swayed by the National Council of Textile Organizations (NCTO) endorsement of CAFTA. Coble voted against trade-promotion authority in 2002.

The pro-CAFTA lobby will hold a coalition meeting with House Republican Whip Roy Blunt (Mo.) on Thursday. The Business Roundtable, a group of chief executives of large American companies, said it is planning a “major lobby day” this month.