The federal government should block mergers of U.S. firms with Chinese telecommunications companies suspected of ties to the Chinese government to lower the potential risk that such firms could serve as conduits for espionage, a congressional panel concluded.

The recommendation is one of several growing out of a nearly year-long investigation by the House Permanent Select Committee on Intelligence, which is set to issue its report Monday. The report accuses two major Chinese telecoms, Huawei and ZTE, of failing to cooperate fully with the panel’s probe into their operations and alleged ties to the Chinese government and military.