The D.C. City Council risks a loss of congressional support for the city if it passes more laws like the new one strictly limiting condominium conversions, three members of Congress warned yesterday.

Despite strongly voiced misgivings over the economic impact of the law, the House District Committee nevertheless unanimously rejected a proposed congressional veto of the council-passed bill, letting it go into effect on schedule next Thursday. Similar stop-gap legislation enacted by the council under emergency provisions already is in effect.

The committee's decision yesterday was based strictly on the principle of home rule -- the right the city gained from Congress in 1975 to enact its own laws, no matter how flawed or wrong-headed and subject to veto only when they clearly conflict with federal interests.

Congress only once had overridden a council act. That was last December when it rejected a measure designed to prevent the location of foreign embassy offices in residentially zoned neighborhoods.

"In my estimation -- though I will not interfere with the city's affairs -- this (condo restriction) is a rotten bill," Rep. Stewart McKinney (R-Conn.), ranking minority member of the committee and a frequent defender of the city, declared yesterday. Because of condominium restrictions, rent control and other economic factors, McKinney said, privately financed apartments are no longer profitable investments in Washington.

The other warnings came from Rep. Millicent Fenwick (R-N.J.), a committee member, and Rep. Charles Wilson (D-Tex.), who introduced the resolution that proposed vetoing the condo bill.

The condo measure requires a majority vote by tenants before any rented apartment building can be converted into condos, gives tenants the first option to purchase the building and grants continued rental rights at legally controlled rents to elderly persons with under $30,000 annual family income as long as the law remains in effect. The council measure will expire in 1983, but is subject to renewal.

Wilson, former chairman of the House D.C. appropriations subcommittee, said the measure and the city's strict rent control law are destroying the local tax base.Because of this, he predicted, the city will encounter real trouble persuading Congress to raise its federal payment in order to prevent municipal bankruptcy.

If housing is needed for renters, Wilson said, government action should take the form of a rent subsidy rogram for the real poor, rather than condo conversion restrictions that are "subsidizing the nonpoor who live in the high-rises on Connecticut Avenue."

Wilson obsevered that "if I were on this (District) committee, I probably would vote against (my own) resolution also," but said he introduced it so he could air his objections.

City Council Chairman Arrington Dixon and city housing director Robert L. Moore both asked the committee, chiefly in the name of home rule, not to veto the measure. Committee Chaiman Ronal V. Dellums (D-Calif.) said rental housing should be made a national priority, and Del. Walter E. Fauntroy (D-D.C.) defended the City Council's right to deal with local problems without congressional interference.