Pro-Carter forces in Florida plan to undertake a lawsuit aimed at knocking independent John B. Anderson off the November ballot, a move that could be crucial to the president's prospects for capturing this tightly contested southern battleground state.

The Florida Democratic Party will file suit in state circuit court in Tallahassee today challenging Anderson's right to be on the ballot because of conflict in the listing of Anderson's vice president running mate, according to the attorney for the state Democratic Party, James D. Whisenand of Miami.

By focusing on the discrepancies in the listing of Anderson's running mates, the suit could open a new avenue of attack for the Carter torces nationally, who have so far met with little success in their previous legal efforts to keep Anderson off ballots in several states.

Anderson has officially designated former Wisconsin governor Patrick J. Lucey as his running mate. But because of early filing deadlines in various states, there are at least 12 different persons listed as the vice presidential candidate on Anderson tickets on various state ballots, according to the suit that was prepared for the complaint in behalf of the Florida Democratic executive committee.

In Florida Milton Eisenhower, brother of the late president, is listed as Anderson's running mate.

Anderson's attorney, Mitchell Rogovin, said that Anderson's campaign would move quickly to counter the suit of the Florida Democrats. "Their suit is feckless, but we'll defend it," he said.

Rogovin said Anderson representatives had asked Florida officials to replace Eisenhower's name with Lucey's, but that the state officials, who are Carter supporters, refused. He said Anderson had planned to file his own suit in Florida to force state officials to replace Eisenhower's name with Lucey's.

Rogovin said some states had already permitted Anderson to change the name of his vice presidential candidate. In other states, he said, the matter is still being negotiated, and where necessary, Anderson's campaign will go to court.

President Carter and Ronald Reagan are now running even in Florida, according to a poll conducted by four state newspapers last week.Carter and Reagan received 28 percent in the poll, Anderson finished with 8 percent and 15 percent of the respondents said they were undecided.

Florida promises to be the major battle ground in the South between the two major party candidates. Carter campaign officials in the state believe that most of Anderson's supporters would not vote for Carter if Anderson were not on the ballot. Before that poll was published, Carter officials had calculated that Anderson could cost the president about 8 or 9 percentage points.

The Florida suit cites three reasons for asking that Anderson be removed from the state ballot. The first focuses on the fact that Anderson's petitions in his original effort to have his name placed on the ballot listed Eisenhower's name as vice president instead of Lucey. Thus, the suit charges, Anderson "intentionally misled" the more than 42,172 Floridians who signed his petitions because the cards do not bear the name of his actual choice for vice president.

Because of this, the suit contends, all of Anderson's petition signatures should be declared invalid.

The second count of the suit also attacks the multiple listings of Anderson's vice presidential running mates. It contends that the multiple listings in the various states are contrary to provisions of both state law and the 12th Amendment to the Constitution.

The suit contends that state law and the 12th Amendment refer to the election of "a" president and "a" vice president, while Anderson in fact has more than one running mate listed on national ballots.

The third count in the suit questions whether Anderson is truly an independent, noting that he is still a member of the Republican Party, serves as a Republican in Congress and ran as a Republican in 21 state primaries.

The Florida suit will represent a new tack in the legal efforts of Carter forces seeking to keep Anderson off state ballots.

In Massachusetts, Carter suporters lost out in their suit contending that Anderson was not an independent for 90 days before the time of his filing, as required by state law, because he had run in the Massachusetts primary as a Republican. The court ruled that Anderson technically had not run as a Republican, only his delegates had.

In North Carolina, the Carter supporters tried to take advantage of the fact that state law requires a truly independent candidates to have more signatures than a third-party candidate, and that Anderson should be removed from the ballot because he did not have enough valid signatures. A federal district court, overturning an earlier legal ruling, said Anderson had enough signatures. An appeal of that case is scheduled for today.

The Florida suit was initiated by state Democratic Party officials, according to Whisenand. The attorney, who prepared the suit for the state Democratic executive committee, said he consulted with the national Democratic Party counsel in preparing the case.

Carter-Mondale campaign officials in Washington said they were informed of the intention to file the suit, but took no active role in preparation of the documents.