Freshman Rep. Richard A. Tonry heavily in debt and dogged by charges that he won a primary race through vote fraud, resigned from Congress yesterday.

The resignation made the Louisiana Democrat the first House member to vacate his eat because of a disputed primary contest, according to House experts.

"I just don't have any more money to fight the court suits on these emerges," a distraught Tonry said yesterday after submitting his resignation to House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass). He said he has re-mortgaged his home, sold several pieces of property and is $300,000 in debt.

Besides that, "Things are so split up and so clouded down there (in Louisiana's First Congressional District). I just felt that this was the best thing to do," he said.

Tonry told O'Neill in his letter of resignation that he intends to run again and win. "Keep my seat warm and tell my colleagues not to forget me," he wrote.

Tonry's resignation came after a long night of his denying rumors and news reports that he intended to step down volutarily. And it came about five hours before the meeting of a three member and the House committee tht had been expected to recommend tht his seat be declared vacant.

The committee with the assistance of the FBI and 10 members of the General Accounting Office, spent the last six weeks checking the results of the Oct. 2, 1976, Democratic primary election in the First District which Tonry won by 184 votes.

The committee met in closed-door session Tuesday to receive a report on that investigation, but declined to recommend any action in the case.

Rep. Mendel J. Davis (D-S.C.), chairman of the ad-hoc group, said afte yesterday's meeting that recommendations affecting Tonry were no longer necessary.

"The question is moot," he said. "There'll be no recommendations made."

But in an afterthought, Davis said: "Actually, the only recommendation I would make is that the governor of Louisiana bring in the U.S. Department of Justice to conduct the next election. I'm going to do that."

Davis would not say how the three-member panel had intended to vote if Tonry had not resigned. But he said the committee's investigation "found that there were voting irregularities on both sides" in the contest between Tonry and former New Orleans City Councilman James A. Moreau.

Louisiana state District Judge Melvin Shortess made a similar finding last week. The judge said a minimum of 229 fraudulent votes had been cast for Tonry and 25 for Moreau, enough to change the outcome of the Oct. 2 election.

"But for the irregularities and fraud, Moreau would have been nominated in the . . . Democratic primary," Shortess said in his 17-page ruling.

The nomination in the traditionally Democratic First District - which encompasses the parishes (counties) of Tammy. Plaquemines, St. Bernard and a large part of Orleans - would have been tantamount to final victory.

In a separate letter of resignation to Louisiana Gov. Edwin W. Edwards, Tonry acknowledged yesterday - as he had done previously - that fraudulent votes were cast in his favor.

"My own personal investigation and that of the(ad-hoc) House committee convinced me that there were fraudulent and illegal votes cast in my favor of my opponent," he wrote. "I sincerely believe and always felt tht if all the fraudulent and illegal votes were subtracted from the total, I would still be declared the winner," he added.

Tonry asked Edwards to "call a new election as soon as possible so that the people of my district will not be without representtion for any significant period of time."

A spokesman for the governor said Edwards if expected today to set a date for special elections - which will include Democratic and Republican primaries and a general race.