While the self-imposed political deadline for a formal Reagan reelection announcement has slipped beyond Labor Day, the White House is gearing up for a second-term try in what participants now refer to as the "provisional campaign" period.

At a recent meeting of top Reagan advisers and strategists, it was decided that White House political director Edward J. Rollins and his deputy, Lee Atwater, would oversee organizational campaign planning during the months ahead, a delicate period in which reelection strategy is molded while the president continues to insist that he has made no decision about whether to seek a second term.

The White House high command and Sen. Paul Laxalt (Nev.), general chairman of the Republican Party, are confident, however, that Reagan will run. They also anticipate that Drew Lewis, former secretary of transportation and now chairman and chief executive officer of Warner Amex, will be able to take a leave of absence sometime in mid-1984 to direct the reelection campaign.

"Among the people who can do the job, Drew is the one who enjoys the confidence of both conservatives and moderates," one White House official said. "He would conduct both a unified and a professional campaign."

Participants in the decision-making meeting were Laxalt, White House chief of staff James A. Baker III, deputy chief of staff Michael K. Deaver and Stuart K. Spencer, the Reagan strategist in the 1980 presidential campaign who is expected to play a similar role in 1984.

White House pollster Richard Wirthlin contributed a memo recommending that F. Clifton White, who managed Reagan's abortive 1968 presidential campaign ef- fort, and Kenny Klinge, a Reagan field operative in 1980, be put in charge of the organizational campaign. Spencer suggested that Republican political consultant Paul Manafort, while Baker and Laxalt favored Rollins to head the provisional campaign.

The decision to rely on Rollins and Atwater emphasizes Baker's authority in the preelection planning and the cooperative association he has forged with presidential intimate Laxalt.

But there will be many mansions in the reelection campaign, as is customary in any Reagan political undertaking. Manafort and his associate Roger Stone, a key Reagan operative in the Northeast during the 1980 campaign, are expected to have a role, along with Klinge and another veteran Reagan political operative, Andy Carter.

White, whose relations with Reagan are of longer standing than any of those mentioned above, is also expected to be included in some capacity. But his status was clouded last week by an incident at the White House illustrative of in-house feuding in the pre-campaign.

Republican sources relate that White called and asked to see the president. Deaver agreed, on condition that White not talk about the campaign. Instead, when the meeting was held, White launched into campaign talk and proceeded, in Deaver's presence, to discuss growing conservative dissatisfaction with Baker and Deaver.

Reagan listened silently to the complaints, as he usually does. But in the elevator with White after they had left the president, Deaver exploded and vowed never to let him near Reagan again.

Now that the administration has recognized the existence of acid rain, look for a new White House attempt to capture this environmental issue from the Democrats with a proposal for a national program that would divide the costs among federal and local governments and private industry.

The outline of a plan proposed by New Hampshire Gov. John H. Sununu (R) seeks the setting of national goals to remove 4 million to 6 million tons of sulfur and nitrogen oxide emissions from the atmosphere annually. At the same time, the president would call for a cooperative crash program involving the federal government and private industry to develop technology permitting greater reductions of emissions in the late 1980s.

Some environmentalists might regard such a plan as far too little and much too late to deal with what is rapidly killing aquatic life in northeastern lakes. But for the Reagan administration, it would represent a leap into the future.

Joanna Bistany, well-regarded aide to White House communications director David R. Gergen, is leaving to become director of public information for ABC. Bistany's departure, Gergen said, "is a real loss for the White House and the president."

Another change in the offing would make White House deputy press secretary Larry Speakes an "assistant to the president," giving him the equal statuswith Gergen that was recommended in a report by personnel director John Herrington.

Reagan returns to the road this week with a political speech today in Mississippi, a speech to the American Medical Association in Chicago Thursday and a flight to Florida the same day to greet the space shuttle astronauts on their return, scheduled for Friday morning.

Reaganism of the Week: (From a speech to the National PTA Convention in Albuquerque last Wednesday): "I confess I was not as attentive as I might have been during my classroom days. I seem to remember my parents being told, 'Young Ron is trying, very trying.' "