WASHINGTON (REUTERS) - Boeing said it will require its 125,000 employees in the United States to be vaccinated by Dec 8 under an executive order issued by President Joe Biden for federal contractors.

"Boeing is requiring its US-based employees to either show proof of vaccination or have an approved reasonable accommodation (based on a disability or sincerely held religious belief) by Dec 8," the largest US planemaker said on Tuesday (Oct 12).

The Society of Professional Engineering Employees in Aerospace union said it was "talking with employers to ensure implementation gives proper consideration to members' concerns, health issues and abides by the provisions of our negotiated contracts".

Just over 5,000 Boeing employees are in Texas, where Republican Governor Greg Abbott issued an executive order on Monday barring Covid-19 vaccine mandates by any entity, including private employers.

"Due to the Texas EO (executive order), the Boeing vaccination requirement announced today does not apply to local sites immediately. However, once these sites become covered under the Biden EO, we expect that they will be subject to the vaccination requirement," a Boeing spokesman said.

Major US airlines have said they will also meet the deadline imposed on federal contractors, including American Airlines, Southwest Airlines, JetBlue Airways and Alaska Airlines, as has aircraft parts manufacturer Spirit AeroSystems.

The White House announced the Dec 8 deadline for employees of federal contractors last month and the requirements are expected to cover millions of employees.

Government contractors International Business Machines and Raytheon Technologies have also said they will require all US employees to be vaccinated.

The White House is adding clauses to future government contracts mandating inoculations.

Mr Steve Cave, a King & Spalding lawyer who specialises in government contracts, told Reuters last month he expects the order will affect tens of millions of US workers or more.

The Labour Department separately plans to issue an emergency temporary standard requiring employers with more than 100 workers to have them inoculated or tested weekly - a policy expected to cover more than 80 million workers.

But that has still not gone to the White House regulatory office for review, suggesting the emergency temporary standard is still at least weeks away.