The powerful heads of the House and Senate foreign affairs committees on Wednesday questioned the legality of President Clinton's decision to allow food sales to Cubans, saying it might violate the Helms-Burton law.

The food sales and other measures easing U.S. sanctions ``breach Congress' intent in codifying the embargo on Cuba under the Libertad Act, said Ben Gilman, R-N.Y., chairman of the House International Relations Committee.

Echoing Gilman's' concerns were Reps. Ileana Ros-Lehtinen and Lincoln Diaz-Balart, both Florida Republicans; and the authors of Helms-Burton, Senate Foreign Relations Committee Chairman Jesse Helms, R-N.C., and Rep. Dan Burton, R-Ind.

Ros-Lehtinen said she, Burton and Diaz-Balart raised their objections at a meeting Wednesday with State Department and Treasury officials who are developing regulations for the changes announced Tuesday by the Clinton administration.

``We want to know where is the legal controlling authority that authorizes them to change the law, Ros-Lehtinen said. ``The way we read Helms-Burton, they do not have any such authority.

The 1996 Helms-Burton law, officially known as the Libertad Act, includes a clause that turned into law all U.S. sanctions then in effect against Cuba. The sanctions had previously been imposed by presidential order. Backers say that means Congress must now approve any significant change in the sanctions.

But the White House had a team of lawyers look at Helms-Burton soon after its adoption and concluded that the executive branch still has the power to tighten or loosen the regulations governing U.S. sanctions on Cuba.

Although the 37-year-old U.S. embargo has always banned food sales to Cuba, the Clinton administration announced Tuesday that it would license U.S. food sales to independent Cubans not tied to President Fidel Castro's government.

While Helms supports some of the other changes announced Tuesday, and he is ready to back ``even bolder moves to promote democracy in Cuba, ``we're concerned that any sale of food probably requires legislation, said Foreign Relations Committee spokesman Mark Thiessen.

Ros-Lehtinen said State and Treasury officials at the meeting Wednesday promised to send her a report arguing that the executive branch did not violate Helms-Burton in easing the sanctions.

``This is just the first stage . . . We'll be haggling about this for a while. There will be lots of paper flying back and forth, and eventually there may be a legal challenge, Ros-Lehtinen said.

Both backers and foes of Helms-Burton have long talked about potential court battles -- backers because President Clinton has repeatedly waived enforcement of certain parts of the law, foes because they argue that the law infringes on the president's right to conduct foreign policy.