Marianne W. Fowler, who was expelled from the Alexandria Democratic Committee last December for her alleged role in helping defeat veteran State Del. James M. Thomson, has refused to return to the party about $500 in funds plus some financial records on grounds that her expulsion was illegal.

Fowler, an ardent feminist who was charged with disorderly conduct in Richmond last week while protesting the defeat of the Equal Rights Amendment in a state legislative committee, is appealing the Democratic committee's action expelling her from her post as party treasurer.

"In the meantime, during the period of appeals," said J. Daniel O'Flaherty, the city Democratic chairman, "we are up a tree without the money or records."

Fowler opened the new bank account at the Arlington Trust Co. last month in the name of the Alexandria Democratic Committee when she discovered that she no longer had access to the party's regular bank acccount. She deposited some party money she had on hand in the new account. Since only she signed the signature card, only she has access to the account.

In expelling Fowler, the city committee accused her of working for the defeat of Thomson, the House majority leader who is a strong opponent of ERA, and for the election of Republican Gary Myers, who promised to support the ERA.Thomson lost and Myers won in the election last Novemeber.

The Eighth District Democratic Committee is scheduled to hear Fowler's appeal tomorrow.

Fowler said in a telephone interview from Richmond yesterday she still considers herself party treasurer and will take her appeal to the Democratic State Central Committee and then to the courts if necessary.

Fowler, who has had four attorneys working on the case, contends that Virginia law makes no provision for expulsion of party officers who have been elected by party members. She says she has continued to attend meetings of the city Democratic Executive Committee and to fulfill other obligations of the party treasurer, including filing reports of financial contributors with the Federal Elections Commision.

Fowler's expulsion has sharply divided the Alexandria Democratic Party.