Neil Bush asked an administrative law judge yesterday to dismiss charges that he violated federal banking law, arguing that it is a "metaphysical impossibility" for the government to seek to bar him from activities at a savings and loan institution that no longer exists.

In asking the judge to dismiss the case on grounds that the penalty sought -- a cease and desist order -- is "illogical," Bush's lawyers stressed they are not in any way admitting that President Bush's son violated conflict of interest rules while serving as a director at Silverado Banking, Savings and Loan Association from mid-1985 to mid-1988. A hearing on the charges is scheduled for Sept. 25 in Denver.

Silverado was closed by federal thrift regulators Nov. 9, 1988, the day after George Bush won the presidential election. The thrift's collapse is expected to cost taxpayers more than $1 billion.

Neil Bush's lawyers argue that a cease and desist order can be applied only in a situation where a person can continue to engage in activities to which government regulators object. Silverado no longer exists, Bush is no longer a thrift director and he no longer does business with the two Silverado borrowers involved in the government's conflict of interest charges, the lawyers say. They argue that as a result, Bush can't possibly repeat his activities at the thrift.

A spokesman for the Office of Thrift Supervision said that because of the Labor Day weekend, no one at the agency was available yesterday to reply to Bush's arguments.

In January, however, when the OTS announced it would seek the cease and desist order, officials indicated the action was intended to apply should Bush ever become involved in banking again. "A cease and desist order ... if granted, would direct Bush not to engage in actions that would constitute a conflict of interest should he ever again serve with a federally insured financial institution," OTS officials said in an official agency statement.