The legal staff of the Federal Election Commission yesterday challenged the plans of Vice President Bush's political action committee (PAC) to recruit and finance candidates for 1986 Michigan precinct delegate election.

In an opinion subject to review by the FEC, the staff took issue with the Bush organization, the Fund for America's Future. The opinion also raises questions about activities on behalf of other prospective candidates, including Rep. Jack Kemp (R-N.Y.), for the 1988 Republican presidential nomination. "These Michigan delegates will form the closed universe of persons who will participate in the process of selecting delegates to the Republican national nominating convention in 1988," Charles N. Steele and N. Bradley Litchfield, of the FEC's legal staff, wrote.

Therefore, money spent to "recruit" candidates, to "disseminate information" and "to make donations to the campaigns" of candidates for precinct delegate must be treated as a campaign contribution in support of a Bush presidential campaign, the staff wrote.

"I am not going to get into a discussion of the staff draft," Jan Baran, the Bush PAC lawyer, said. He said staff opinions have "a propensity for getting changed at the commission level." The commission is politically appointed, and made up of three Republicans and three Democrats.

The staff opinion, if upheld, suggests that Bush's use of the Fund for America's Future to finance an office with three full-time staff workers in Michigan may be illegal and that the announced plans of the fund to recruit and finance delegate candidates would be illegal.

The Fund for America's Future is a PAC legally restricted to helping candidates for House, Senate and local offices, and cannot be used as a vehicle to finance a presidential bid.

The FEC staff opinion said that recruiting and financing precinct delegate candidates in the August primary in Michigan amounts to financing the early stages of a presidential contest.

The 1986 Michigan contest is widely accepted among all the prospective presidential candidates as the first test in the 1988 GOP nomination process, preceding by well over a year the Iowa caucuses and the New Hampshire primary.

The FEC staff opinion, which will be reviewed by the FEC, could be interpreted as raising identical issues for other prospective candidates.

An organization called the Michigan Opportunity Society, run by Clark Durant III, chairman of the Legal Services Administration, has been acting as a de facto arm of the Kemp campaign, recruiting candidates to run for precinct delegate.

John Buckley, press aide to Kemp, said that the Michigan Opportunity Society is a spontaneous, independent group acting at arms' length from Kemp's PAC, the Campaign for Prosperity, in contrast to the activities in Michigan in support of Bush, which are "an arm of the Bush PAC."

Democratic and Republican politicians considering presidential bids have been making increased use of "multicandidate" PACs to finance travel, staff, mailings and other costs that have the appearance, if not the substance, of a presidential campaign.

Federal law has created many incentives to candidates to use these special multicandidate PACs, instead of formal presidential campaign committees, to finance their activities.

Among the incentives are the fact that special PACs can accept $5,000 from individuals, in contrast with a $1,000 limit for presidential committees; that money spent by the PACs does not count against spending limits, and that establishment of a presidential committee now means that contributions will not qualify for federal matching money because matching money applies only to gifts received after Jan. 1, 1987.