Business groups are lobbying intensely to defeat a bill -- scheduled to come up in the House today -- that would limit the campaign contributions they can make to candidates for House seats.

Sponsored by Reps. David Obey (D-Wis.) and Tom Railsback (R-Ill.), the legislation says no House candidate could accept more than $70,000 in contributions from special-interest political action committees in any two-year election cycle.

Contributions from PACs to House candidates have nearly tripled since 1974 when PACs contributed $8.3 million. By 1978, that figure was up to $22.9 million.

Obey and Railsback claim the PACs are, in effect, "putting Congress on the auction block," and buying legislation that protects their interests by making big contributions to the candidate.

Business and Republicans, on the other hand, see the Obey-Railsback bill as an attempt to insulate incumbents from challengers and as a way to prevent proliferating contributions from business.

"Everybody knows that anything which sets the same ceiling for incumbents and challengers favors incumbents. Challengers just need more money to beat incumbents," Hilton Davis, lobbyist for the Chamber of Commerce, says. "Why weren't they complaining about PACs when only the unions had them?"

Unions were allowed to solicit members for contributions, but corporations were not, until a court ruled both unions and corporations must be allowed equal access to their membership. That decision set off their current proliferation of business PACs.

Allied with Obey and Railback are about 130 of their colleagues, plus so-called citizens groups, such as Common Cause, the League of Women Voters, Ralph Nader's Congress Watch and the Urban Coalition.

Obey-Railsback is also supported by the AFL-CIO, but union support is not universal. The UAW, for instance, is neutral. Labor unions, watching the proliferation of business PACs, realize the number of unions isn't going to expand. The unions' only hope of keeping up with business is by contributing greater amounts, some union members feel.

Both sides agree the vote on the bill will be close. Lobbying has been heavy, with the normal processes of persuasion sometimes giving way to near threats.

At a Democratic Campaign Committee seminar last weekend, for example, Bernadette Budde, an official of the Business-Industry Political Action Committee (BIPAC), made clear Obey-Railsback would be regarded as a key vote, and a vote in support might "make it more difficult for a candidate to get business PAC money," one participant reported.

"It was't exactly a threat, but the implication was clearly there," said a House staffer who attended the meeting.

Budde said, "It was in no way a threat, but I was trying to be as honest as I could as to what chances Democratic incumbents have for raising business money."

"I'm amazed at the intensity of the lobbying," Railsback remarked.

As part of this process, Rep. Mendel Davis (D-S.C.), a leading opponent, maneuvered two weeks ago to have the bill delayed to leave more time for lobbying over the Columbus Day recess.

The House leadership had the Obey-Railsback bill on the schedule, but also needed more votes to pass a once-defeated budget resolution. Davis produced 11 budget resolution votes and in return the leadership took the campaign contribution bill off the calendar.

"It was a boneheaded deal," Obey said. "Horse trading goes on all the time, but the price was too high." Obey contends this will be the last chance Democrats have to contain special interest contributions. He predicts that the contributions which now go mainly to Demoratic incumbents will begin to shift to Republicans as business becomes more confident in its electioneering. "After this year, they'll be too big and too powerful to stop," Obey said.

While there is now no limit on how much money House candidates can take from PACs overall, there is a limit on what a single political action committee can contribute to a candidate. The limit is now $5,000 in a primary and $5,000 in a general election or $10,000 combined. The new limit proposed by the Obey-Railsback bill would be $3,000 in a primary and $3,000 in a general election for a $6,000 overall limit. The limits go slightly higher in case of a runoff.