Senate Republicans expressed confidence Monday that they would block not only a hotly contested “card-check” union organizing bill but also language granting airport screeners collective bargaining rights as well as other legislation aggressively being sought by labor unions.

“We’re just not going to let the federal government force unionization,” Minority Whip Trent Lott (R-Miss.) told CongressNow.

The Senate is expected to vote Tuesday on S. 4, which would implement the recommendations of the 9/11 commission. That bill contains a provision that would give Transportation Security Administration employees the ability to unionize — language that was pointedly left out of the legislation that created the TSA in 2002 and that was used to great effect as a wedge by Republicans in that fall’s midterm elections.

Lott is part of a coalition of 36 lawmakers who are promising to vote to uphold a promised presidential veto. The bill’s opponents argue that granting airport screeners collective bargaining rights would undermine the TSA’s flexibility necessary to stay a step ahead of terrorist groups.

These lawmakers sent a letter Feb. 27 to the White House promising their support for President Bush’s promised veto of language that would give airport screeners the ability to unionize. “If the final bill contains such a provision, forcing you to veto it, we pledge to sustain your veto,” the letter said.

Senate Democrats would need two-thirds of the chamber, or 67 votes, to override a presidential veto.

These opponents, which include Sen. Jim DeMint (R-S.C.), are simultaneously gearing to fight a broader bill authorizing creation of a union if a majority of employees sign cards in favor of doing so. Union organizing elections are currently held by a secret-ballot vote.

That “card-check” bill is “dead on arrival,” because of strong Republican opposition, an aide for DeMint said.

Bush already has promised to veto this bill. Also, Lott has pledged to filibuster the bill.

But Sen. Edward Kennedy (D-Mass.) was not ready to concede on the card-check legislation.

“It’s unclear” whether the TSA vote will do much to predict the outcome of the secret-ballot vote, a Kennedy aide said. The fact that there was broad support for the bill in the House bodes well for its chances, the aide added. The House bill, H.R. 800, passed March 1 by a vote of 241 to 185.