A federal grand jury in New York still is examining the activities of former Democratic National Committee chairman John C. White, and a charge that he was offered a $1 million campaign contribution in return for political favors may be a reason for the lingering investigation.

It clearly is exasperating to White and his attorney, Stuart F. Pierson. "John is irate as an individual. It is ironic to him that he has cooperated and is still twisting in the wind," Pierson said recently. "The prosecutors seem to be trying to dot every 'i' and cross every 't' in case anyone ever looks at this case someday. And this latest charge is coming from a liar and a swindler."

James C. Day, a Texas political acquiantance of White's who pleaded guilty last fall to trying to con the Libyan government in a scheme to free embargoed airplanes, testified about the $1 million offer in a court hearing on an unrelated case in Denver in early April.

"John, if you will help me on this thing and if I get it done, you've got my commitment you'll have $1 million for your governor's race," Day recalled telling White in the spring of 1979 when he was pushing to get a lucrative lobbying contract from the Libyans. He said White responded, "That's absolutely fantastic, that's great."

White acknowledged at the same hearing that Day had mentioned a contribution, but denied any $1 million figure was discussed and said the talk was unrelated to Libya. "I know he enver promised to give me any money for any particular purpose," White testified.

Day's charge about a $1 million campaign contribution is the first public indication that White may have had an incentive for helping Day other than as a political ally. White has acknowledged making calls to State Department officials asking about the status of the planes Libya was seeking to have released from embargo, and meeting the Libyan ambassador and Day on the Hotel Washington rooftop. The encounter was secretly photographed by the FBI.

White appeared twice before the New York grand jury, which reportedly is considering the possibility of perjury charges against him. Prosecutor Raymond A. Levites refused to comment on the case except to say the grand jury still is investigating the Libyan matter.

Pierson said that his client considered his meetings with Day, the phone calls to State and the rooftop meeting with the Libyan ambassador "an insignificant courtesy. . . . He wanted to keep him [Day] happy. He has spent most of his life trying to keep people happy."

"Essentially this is a swearing match between Jimmy Day and John White," Pierson said of the $1 million contribution charge. He said Day hopes testimony against White could lead to a reduction in the four-year sentence he is serving for his part in the Libyan scheme.

When he pleaded guilty last November, the conspiracy charge said Day "did falsely represent the nature and extent of the actions that John C. White would undertake to assist Day in his efforts on behalf of the Libyan government." For instance, the government charged that Day arranged for a man to pose as a White aide in a meeting with fugitive financier Robert Vesco. Day also falsely claimed he had promised to pay White $14,000 to buy a car, the court papers said.

Pierson said he was frustrated because after more than two years of investigation, the grand jury still has not made a decision about his client. "It [the case] should be closed. The grand jury should have more than enough information to reach a decision."

White said in a recent phone interview that he felt "quite comfortable" about the grand jury inquiry. "I've had no real concern from the beginning," he said. He said he is now doing some government consulting and tending to persnal investments in Texas. The 56-year-old White served as agriculture secretary in Texas for 27 years before moving to Washington to be deputy secretary of agriculture and the DNC chairman during the Carter administration.

White declined to discuss any future plans for a political race in ytexas. "I'll talk to the Texas press about that when the time comes," he said. "It's [a possible run for governor] not on the front burner now. It's not even on the back burner."