US labour unions are not pleased with the plan to launch a US Virgin Islands flag state.

The heads of eight maritime unions published a statement on Tuesday slamming the concept as a way to enrich foreign shipowners at the expense of US interests.

“The proposed US Virgin Islands flag of convenience open registry will not benefit the United States nor America’s maritime industry, any more than any other second or open registry benefits a national flag country,” said the labour leaders, who included the heads of the American Maritime Officers, the Marine Engineers’ Beneficial Association and International Organization of Masters, Mates & Pilot.

“At its core, this proposal, allowing for the operation of vessels with foreign mariners under a United States open registry, is an affront to the American mariners who have always put themselves in harm’s way whenever called upon by our nation.”

In addition to the three unions, the Sailors Union of the Pacific, the AFL-CIO’s maritime and transportation trades departments, the Marine Fireman’s Union and the Seafarers International Union signed the statement.

As it stands, in order to fly the US flag, a ship must be built, owned and crewed by Americans.

While there are few details on what rules and requirements the US Virgin Islands flag would have, Northeast Maritime Institute president Eric Dawicki said the registry would be an “ally” for seafarers.

Dawicki, who signed an agreement to develop the registry with US Virgin Islands Governor Albert Bryan in Washington, DC on Tuesday, also said the registry would be transparent and help the shipping cut emissions while bolstering national defence.

He said the plan had broad support, with just a few, unnamed holdouts.

The unions shot back that the proposed US Virgin Islands registry would simply exacerbate the US reliance on foreign ships and seafarers, “not somehow magically enhance America’s maritime posture”.

“We call upon the Department of Defense, the Maritime Administration, the Biden administration and the Congress to reject any suggestion that the United States Virgin Islands-flag vessels be treated as if they are US-flag and US-crewed vessels for any purpose or for any programme,” the unions said.

“At the same time, we reiterate our commitment to work with the administration and Congress to achieve a more robust, commercially viable US-flag, US-crewed fleet that will continue to protect America’s economic, military and homeland security.”