Unless the Secretary of the Treasury finds that the collection of a tax is in jeopardy, in carrying out the provisions of section
4975 of title
26 (relating to tax on prohibited transactions) the Secretary of the Treasury shall, in accordance with the provisions of subsection (h) of such section, notify the Secretary of Labor before sending a notice of deficiency with respect to the tax imposed by subsection (a) or (b) of such section, and, in accordance with the provisions of subsection (h) of such section, afford the Secretary an opportunity to comment on the imposition of the tax in any case. The Secretary of the Treasury shall have authority to waive the imposition of the tax imposed under section
4975
(b) in appropriate cases. Upon receiving a written request from the Secretary of Labor or from the Pension Benefit Guaranty Corporation, the Secretary of the Treasury shall cause an investigation to be carried out with respect to whether the tax imposed by section
4975 of title
26 should be applied to any person referred to in the request.