They are descendants of some of the first residents of this continent, but it is taking 11th-hour action by Congress to keep Native Americans born in Canada from losing federal benefits under a Welfare Reform Act provision aimed at immigrants.

In New England and elsewhere, Native Americans born in Canada are receiving notice that they are about to lose their Supplemental Security Income checks. Under the same law, they also stand to lose their rights to food stamps.

The notices — which most government offices have just become aware of — are being called by advocates one more example of government ignorance about Native Americans’ special status in the United States. As government officials become aware of this unforeseen effect of the 1996 law, they are scrambling to correct it.

“Native Americans are not immigrants,” protested Leona Phillips of Boston, a 50-year-old, disabled Micmac who was born in Canada and has lived in New England for 30 years. “I got [the cutoff notice] and tossed it in a pile,” convinced it was a mistake, she said.

But it’s not. Phillips is one of a disputed number of hundreds or thousands of Canadian-born Native Americans in this country who have been inadvertently wiped off benefit rolls as part of the sweeping Welfare Reform Act passed last year.

The Welfare Reform Act was enacted last year to eliminate SSI and food stamps for most legal immigrants by this summer. Because of public outcry, Congress is considering restoring benefits to other groups as well.