The idea of raiding tax-deferred retirement savings for first-time home purchases is back on the table as the process of budgeting for the federal government's next fiscal year gets underway.

Although much of the housing-related budget debate will focus on sheltering the country's poor, the issue of tapping individual retirement accounts (IRAs) is one of a few that could have an impact on middle-class families.

Other proposals could potentially discourage military veterans from using their housing finance benefits more than once and effectively kill a pilot subsidy program to lower mortgage interest rates to 6 percent for first-time buyers by failing to fund the program.

Federal lawmakers have tossed around the notion of linking IRAs and home purchases for several years, but this time the political climate could prove more receptive to the idea, some housing officials said they believe.

For the second year in a row, President Bush has proposed liberalizing IRA rules for first-time buyers as part of his budget plan.

The latest administration proposal would permit qualifying home buyers to withdraw up to $10,000 from their IRAs without penalty to buy a home priced at no more than 110 percent of their community's average price. Although home buyers would not incur the 10 percent penalty on early withdrawals made before reaching age 59 1/2, they would still owe taxes on the sum withdrawn.

A counterproposal reintroduced by Sen. Lloyd Bentsen (D-Tex.), head of the Senate Finance Committee -- but this time with co-sponsorship from Sen. William V. Roth Jr. (R-Del.) -- would expand the IRA-homeownership concept in several ways.

For the first time, parents and grandparents could, without penalty, tap into some or all of their IRA savings to help their adult children or grandchildren buy first homes. The home buyers themselves could also raid any existing or future IRA funds without limit.

Ostensibly, such a move would make the $500 billion that the Investment Company Institute estimates is the total value of all IRA accounts in the country available to fund first-time home purchases. The Institute represents the mutual fund industry.

In addition, the Bentsen-Roth plan would also open up employer-provided retirement plans such as 401(k) accounts as a source of funds to first-time home buyers. Borrowers, parents and grandparents could, again, dip into some or all of these retirement plans without triggering the 10 percent penalty for early withdrawal.

At the end of 1987, according to the most recent figures available from the Department of Labor, $215 billion was deposited in 401(k) plans.

The Bentsen-Roth plan also gives any taxpayer the option of contributing up to $2,000 annually for at least five years to a new type of "back-end" IRA. After five years, the income earned on the account would be tax-free upon withdrawal, but the contributions themselves would not be tax deductible.

Moreover, the Bentsen-Roth plan would restore the full tax deductibility of IRAs that was eliminated under the 1986 tax reform law, which should make the accounts a more attractive investment, a Senate staff member said.

Although the cost of the proposal has not been calculated at this point, the Senate staff aide said he does not believe it would cost much more than $400 million the Treasury Department has projected the Bush plan will cost over five years. However, other components of the Bentsen-Roth proposal that would make IRA money available for educational and medical purposes would add to the price tag.

Ken Beirne, vice president of government relations for the National Association of Realtors, said he believes the Bentsen-Roth approach stands the better chance of passage.

"In the past, IRA plans {similar to what the administration is proposing} have all been so narrow that it was hard to generate large-scale enthusiasm, but the parents and grandparents provision {of the Bentsen-Roth plan} widens out the opportunity," Beirne said.

However, Robert Bannister, chief lobbyist for the National Association of Home Builders, gives the Bush proposal the greater chance of enactment because he believes it is the "more modest" of the two in terms of cost.

Bannister said he is convinced some IRA home purchase plan will be approved this time because Congress is looking for a low-cost way of giving the ailing housing industry a boost so it could, in turn, lead the country out of the recession.

In the opposite corner, Robert S. McIntyre, director of Citizens for Tax Justice, predicted that neither version will pass because Congress will ultimately realize that IRAs do not increase the country's savings rate, and will be unwilling to cut back existing programs to pay for a new venture.

The Bush administration budget proposal also calls for increasing the costs for repeat users of the Department of Veterans Affairs home loan guarantee program. Such borrowers account for 20 percent of VA loans currently made. Borrowers could still get an initial VA mortgage with nothing down, but for subsequent house purchases would have to make a 10 percent down payment. The 1.875 percent origination fee also would rise for repeat borrowers to 2.5 percent.

Warren Lasko, executive vice president of the Mortgage Bankers Association of America, said the proposed changes are "clearly aimed at discouraging people from using the program."

Foreclosures among repeat borrowers, House Veterans Affairs Committee spokesman Jim Holley said, are 25 percent lower than for first-time buyers. Consequently, Holley said he doubts the proposal will make it far in Congress.

Keith Pedigo, VA's director of loan guaranty service, defended the proposals, saying they were designed to cut loan losses. Over the last eight years, Congress has had to appropriate about $3 billion to sustain the program. The changes, Pedigo said, will save a projected $59 million in 1992.

Qualifying first-time home buyers could also lose out on 6 percent mortgage rates if the administration succeeds in choking off funding for the National Housing Trust Fund, a $520 million interest rate subsidy program authorized under last year's affordable housing law.

When questioned about the funding omission, Housing and Urban Development Secretary Jack Kemp said that the proposed budget reflects different priorities held by the administration. Nothing about the budget is as yet set "in concrete," he said, adding that he expects some kind of congressional push for funding of the program.