An agency undergoing layoff shall, prior to implementing a layoff, notify the Department of the impending layoff so that the Department may determine the applicability of Government Code section 19798. If federal law or the United States Constitution requires the adjustment of the order of layoff pursuant to Government Code section 19798, or if the failure to adjust the order of layoff in accordance with Government Code section 19798 would result in ineligibility for a federal program and a loss of federal funds, an agency may not proceed with a seniority-based layoff, but may have to adjust the order of layoff under the circumstances set forth in section 599.844.2 of these regulations.