Updated

The charges against former Enron Corp. executives Ken Lay (search) and Jeffrey Skilling (search) are too vague for them to defend themselves against, lawyers for the two argued in filings submitted to a U.S. District Court Friday.

Lay, the former Enron chairman, and Skilling, the company's former chief executive, are asking the federal court to force prosecutors to lay out the specific incidents where they broke the law and to identify unnamed co-conspirators listed throughout the indictment.

"The vague and sprawling Indictment against Jeffrey Skilling potentially places at issue every transaction, public statement, and SEC (search) filing involough its bankruptcy in December 2001," Daniel Petrocelli, lead attorney for Skilling, said in a court filing.

Lay was added to the indictment against Skilling and former Chief Accounting Officer Richard Causey in July. All three are charged with fraud and conspiring to illegally boost the former energy company's revenues. Skilling and Causey also face charges of insider trading, while Lay is charged with illegally using personal bank loans to buy stock on margin.

Enron Corp. (search) collapsed into the largest bankruptcy of its time in December 2001 as the energy trading company's use of off-the-books partnerships to hide massive debts was exposed.

Lay's lawyer Michael Ramsey argued in a filing that prosecutors must detail each public statement made by Lay that they believe constituted a crime.

"It is imperative that defense counsel be specifically informed as to the substance of any and all statements purportedly made by Mr. Lay that the government plans to use at trial," Ramsey said in the court filing.

In a separate filing, prosecutors from the Department of Justice's Enron Taskforce said motions filed by Lay, Skilling and Causey last month seeking separate trials should be denied because the three were all part of the same conspiracy.

"The challenged counts overlap with the single overarching conspiracy with which all the defendants are charged," Andrew Weissmann, director of the task force said in the government's filing.