A House subcommittee chairman said yesterday that defrocked televangelist Jim Bakker and his wife Tammy Faye will be asked to testify at an Oct. 6 hearing on the tax status of television ministries.

The Bakkers face a Justice Department criminal investigation for their management of the PTL ministry. Their lawyer, Melvin Belli, said he could not guarantee the couple's appearance, but added, "I'm going to recommend that the Bakkers be present . . . and I will be there -- if they're willing to do it."

The upcoming hearings, which have drawn sharp criticism from some religious groups, have been prompted by the PTL scandal. Rep. J.J. Pickle (D-Tex.), chairman of the House Ways and Means oversight subcommittee, said the affair has raised questions about the "administration and enforcement" of tax laws as they apply to tax-exempt TV ministries. Pickle, a soft-spoken middle-of-the-roader who has rarely courted publicity in his 23 years on Capitol Hill, said repeatedly yesterday that he does not plan to stage a full-blown investigation into the practices of America's leading televangelists. Nor, he said, does he want to push legislation that would infringe on First Amendment rights.

"The public contributes millions of dollars each year to television ministries which operate in full or in part as tax-exempt organizations," said Pickle at a news conference. "Recent events have raised questions which need to be explained."

"We're not questioning or investigating anyone . . . and we're not trying to change the law," he added at another point. "We're going to be interested in the Internal Revenue's prompt and even-handed application of the tax laws."

Nevertheless, many observers believe that Pickle's witness list guarantees him klieg lights and headlines. Besides the Bakkers, whose every utterance has made news the past few months, Pickle disclosed that his panel will send formal invitations to Republican presidential hopeful Pat Robertson, Moral Majority founder and current PTL leader Jerry Falwell, and other televangelists including Jimmy Swaggart, B. James Kennedy, John Ankerberg, Paul Crouch, Billy Graham, Oral Roberts and Robert Schuller.

Pickle last month privately met with Falwell and a representative of the National Religious Broadcasters, both of whom expressed cautious support for the hearings. But at least one TV minister -- Ernest Angley -- has already said he would not plan to show up. Subcommittee staffers also said yesterday that "hundreds of letters" have expressed fears that Pickle was trying to remove TV ministries from the airwaves.

One subcommittee staffer said the letter writing appeared to be organized, apparently by Paul Crouch's California-based Trinity Broadcasting Network, which is specifically mentioned in most of the letters. Crouch did not return a phone call to his office yesterday.

"I'm getting a lot of mail from the public, from all over the country, saying we're trying to take {the ministries} off the air," said Pickle. "Nothing is further from the truth. We're not going to take anyone off the air."