The Reagan administration is drafting legislation to put a cap on legal fees awarded in successful "public interest" lawsuits against state, local and federal government agencies for violations of federal laws.

The administration bill would also significantly increase fees for lawyers appointed to represent indigent criminal defendants. Low fees have prompted public-defender protests across the country, including a recent work stoppage in Washington.

The administration is linking the two fee proposals in its "Legal Fees Reform Act" in an apparent effort to counter criticism that the first proposal is already drawing from organizations concerned with civil rights and civil liberties.

The first proposal involves federal laws that require government agencies to foot the bill of attorneys who successfully sue them for violations of a wide variety of civil rights, environmental protection, freedom of information and other statutes.

The system was designed to encourage enforcement action by private individuals as a supplement to government enforcement. But it has also sparked mounting complaints, not only from conservatives in the Reagan administration but from state and local officials, whose governments must pay the bills and fight the suits.

Currently, no limit exists on hourly rates, which can range up to $150 plus bonuses for especially complex cases. The administration proposal would place a $75-per-hour cap on the fees, according to those who have reviewed the draft. Other provisions would give officials flexibility to reduce fees beyond that level or deny them entirely in some circumstances.

Administration officials would not comment publicly on the proposal, although a high-level source confirmed its details. Representatives of several public-interest organizations have reviewed the draft.

Nan Aron, director of the Alliance for Justice, an umbrella group of public-interest law organizations, said that the proposal "would make citizens who sue the government basically second-class citizens in the courts." She said that the proposal "is based on the assumption that lawyers are getting rich off these fees. That couldn't be further from the truth."

An administration official, who asked not to be identified, said that the current system has created a "mushrooming industry" dedicated to filing contingency-fee suits against the "deep-pocketed" government defendants. The two fee proposals are an attempt, he said, to correct a "distortion in the system" that finds lawyers in successful civil suits paid two, three or even four times the hourly rates paid lawyers representing indigent criminal defendants.

The criminal defense lawyers portion of the bill would double the hourly rate for federal cases from $30 to $60.

The National Association of Attorneys General is preparing its own report recommending limits on the fee awards in civil cases. Thomas Carr, an assistant attorney general for the state of Washington who is preparing that report, said that $90 to $120-an-hour is a typical fee for such cases in his state, with occasional examples of $300-an-hour fees.

"I come from liberal Democratic stock," he said. "But when I get on to this subject I froth at the mouth. The basic concept of attorneys fees awards is a good one, but we are getting tagged for too much."