President Barack Obama used a Labor Day speech to denounce Republicans for a "constant attack on working Americans" as he signed an executive order extending paid sick leave to an additional 300,000 federal workers.

Those working on federal contracts will have the opportunity to earn up to seven sick days per year, depending on how many hours they work, according to a release from the White House. The statement said the changes will go into effect with new contracts beginning in 2017 — just as Obama prepares to leave office.

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The White House wouldn't specify the cost federal contractors would face to implement the executive order.

The president's Labor Day announcement came with a call for Congress to follow his lead and pass the Healthy Families Act, which would require businesses with more than 14 employees to similarly offer seven days of paid sick leave.

Obama also called on states to pass laws that expand paid sick leave to all workers. Obama's 2016 budget includes $2 billion for states to do just that as well as create laws that would allow employees maternity, paternity and eldercare leave.

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