Hundreds of employees from some of Britain's biggest contractors are temporarily out of work, as a result of the U.S. political stalemate that has led to a partial shutdown of the country's government.

Those hit include aerospace and defense giant BAE Systems, security services specialist G4S, and Serco, which provides personnel services to governments.

In a statement on Thursday, BAE said that approximately 1,200 employees across its intelligence and security and support solutions businesses in the U.S. had been told not to turn up for work.

"Whilst the impact of this action has not yet been material to the group's overall financial performance, some progressive impact to the group's U.S. operations would result from a protracted government shutdown," BAE said in its interim statement for the third quarter of the year.

The federal government has remained partially closed since October 1, with a dispute over President Barack Obama's Affordable Care Act leading to Democrats and Republicans failing to strike a deal on how to fund the government until year-end.

Approximately 800,000 federal workers were sent home without pay at the beginning of October, although the number out of work is now closer to 450,000, after the Pentagon ordered most of its employees back to work this week. Those still locked out include government scientists and economists, and employees of visitor attractions such as museums and national parks.

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