Members of the House and Senate yesterday introduced legislation to change the way Congress can veto District of Columbia laws, in an effort to remove a cloud over the constitutionality of the Home Rule Act that for a decade has given the city authority to legislate for itself.

City Council member John Ray (D-At large), meanwhile, agreed to postpone final council action on his bill that would prohibit any District investments in banks or corporations doing business with South Africa.

Ray agreed to the last-minute delay in order to give Congress time to clarify the home rule situation before his controversial measure goes to the Hill for consideration.

The bills introduced in the House and Senate would enable Congress to overturn city-approved legislation by a joint resolution that then would have to be approved by the president. Currently, District bills can be vetoed by a majority vote of one or both houses of Congress, depending upon the type of legislation, and the veto does not require presidential approval.

Congressional aides said that the reform measures may be brought to the floors of both houses for a vote as early as next week.

The Supreme Court ruled recently that congressional vetoes are unconstitutional, casting doubt upon the constitutionality of some 200 current laws, including the act that mandated home rule.

Legislative experts are uncertain whether the ruling would apply to the home rule act, since the Constitution gives Congress specific and exclusive legislative authority over the District.

But District officials and the city's friends on Capitol Hill want to clarify the situation before the act and the laws enacted under it can be challenged in the courts and perhaps ruled invalid.

Members of Congress have been urging the City Council to tread lightly until this issue is resolved and not send to the Hill any controversial legislation that could trigger congressional action.

Friends of the District in Congress have warned that the losers on either side in any veto fight might challenge the outcome in court.

Until yesterday, Ray had dismissed these fears as "silly." But just before the council was scheduled to give final approval to his bill on ties with South Africa, Ray withdrew his measure for two weeks at the request of Mayor Marion Barry and Council Chairman David A. Clarke.

The bill, which city officials say the mayor has promised to sign, would require divestiture of millions of dollars in city investments in 31 businesses that have dealings with South Africa and would require the removal of city funds from accounts at American Security and Riggs National Bank, according to Ray's office. The proposed legislation is expected to attract strong opposition from business interests and some members of Congress.

The bill to amend the Home Rule Act was introduced by Sens. Charles McC. Mathias (R-Md.) and Thomas Eagleton (D-Mo.), chairman and ranking minority member, respectively, of the Senate Government Operations District subcommittee. In the House, a similar measure was introduced by D.C. Delegate Walter E. Fauntroy.

Introducing his bill, Mathias called it a "consensus approach to meet the urgent situation which faces the District of Columbia."

The sponsors pointed out that the city has not been able to issue bonds since the Supreme Court ruling, because of the cloud over home rule authority.

A House District committee staff aide said that Fauntroy plans to bring his proposal up for consideration at a committee meeting today and that it could go to the House floor on Monday.

Rep. Stewart McKinney (R-Conn.), ranking minority member, supports the bill but is concerned about moving too quickly on it without hearings or consultations with committee Republicans, said John Gnorski, the committee's minority counsel.

Under a bill being considered by the D.C. City Council, District banks would have to file an affidavit with the city declaring that they have no outstanding loans with South Africa to be eligible to get or keep city accounts. Two banks, Riggs and American Security, have so far declined to tell the city whether they have such loans. If the bill passes, they would have two years to comply with the provisions. This time element was not clear in an article yesterday.