WASHINGTON (AP) _ The mail fraud conspiracy trial of political maverick Lyndon LaRouche and six associates went to a federal jury Thursday, with defense lawyers proclaiming their innocence and government prosecutors charging they had committed ''an enormous crime - a $30 million crime.''

After explaining the legal complexities for nearly an hour, Chief U.S. District Judge Albert V. Bryan Jr. sent the case to the jury of eight women and four men at midday, as Christmas carols chimed from a church tower outside the courtroom.

Bryan had said the jurors would deliberate through Saturday, if necessary, to reach a verdict in the case involving LaRouche, 66, head of a controversial political movement and a perennial independent presidential candidate.

LaRouche did not testify in his own defense during the 15-day trial, but Bryan cautioned jurors not to let that influence their decision.

The judge also said LaRouche's political views were irrelevant to the case, and Assistant U.S. Attorney Kent Robinson denied defense lawyers' suggestions that the government was trying to ''get at Mr. LaRouche or quiet a political movement.''

LaRouche and six of his fund-raisers and other aides are charged with mail fraud and conspiracy in an alleged scheme to raise more than $30 million in loans from supporters without any intention of repaying them.

In addition, LaRouche is accused of conspiring to defraud the Internal Revenue Service by having all his personal expenses - housing, meals, clothing, travel and even haircuts - paid by various corporations he controls, and claiming he had no taxable income.

LaRouche has not filed federal income tax returns for any year since 1978, government prosecutors said. His lawyers contended he had received ''non- taxable compensation'' as an employee of his organization.

If convicted of all 13 counts against him, LaRouche faces a maximum penalty of 65 years in prison and fines totaling $3.25 million.

In the final closing defense argument, attorney Michael Reilly said his client, fund-raiser Paul Greenberg, and his colleagues solicited loans with good-faith assurances that they would be repaid as promised.

Waving his arm at each of the seven defendants, Reilly told the jurors, ''They are not guilty, and I ask you to say so.''

In his rebuttal, Robinson said LaRouche and his associates knew their organization was in such dire financial straits that it was ''a bankruptcy waiting to happen,'' but that they never warned prospective lenders they probably wouldn't get their money back.

Defense lawyers asked the jurors to question why LaRouche fund-raisers would ''cut off their life blood'' by defrauding loyal supporters. To this, Robinson responded that ''they weren't the life blood of this organization. These supporters were being bled dry.''

Robinson accused the LaRouche people of treating their lenders with ''cynicism and disregard,'' an attitude he said resulted in ''an enormous crime - a $30 million crime.''

He said there was only one issue to decide: ''Did the defendants tell the truth when they tried to borrow money from people - did they tell the truth, or did they lie?''

Bryan reminded the jurors that membership in a political organization, even one with ''honest albeit controversial views,'' is lawful under the Constitution and is not evidence of any criminal activity.

LaRouche's political movement embraces a number of unorthodox positions, and relies heavily on conspiracy theories to explain world events. It has alleged that prominent figures suchy as former Secretary of State Henry Kissinger and Britain's Queen Elizabeth participate in those conspiracies.

Some Larouche supporters also have advocated a quarantine for AIDS victims and have been accused of harboring anti-Semitic views.