WASHINGTON  Former Attorney General John Ashcroft responded angrily on Tuesday to Congressional Democrats who suggested that a no-bid private contract awarded to him by the Justice Department last year amounted to a “backroom, sweetheart deal” that would earn his consulting firm tens of millions of dollars.

“There is not a conflict, there is not an appearance of a conflict,” Mr. Ashcroft said at a hearing of a House Judiciary subcommittee called to explore the circumstances of the contract.

He repeatedly tried to talk over the panel’s Democratic chairwoman, Representative Linda T. Sanchez of California, who offered the harshest questioning of Mr. Ashcroft, a Republican. The former attorney general stepped down from the Justice Department three years ago and now runs a Washington consulting firm that bears his name.

Ms. Sanchez opened the hearing by suggesting that the department’s decision last year to award a monitoring contract worth between $28 million to $52 million to Mr. Ashcroft’s firm, as part of an out-of-court settlement with a medical supply company under criminal investigation, presented the appearance of a conflict, since it was made by officials who had been Mr. Ashcroft’s subordinates.