The Federal Trade Commission is challenging the proposed merger of Framingham-based Staples and Office Depot.

Staples is willing to pay $6.3 billion to buy rival Office Depot, but the FTC wants to stop the merger because they say it would reduce competition and likely drive up prices.

It’s not that the FTC is worried about the average person paying more for post-it notes. Their complaint specifically relates to competition for large business customers. The agency is seeking a temporary restraining order and a preliminary injunction to stop the merger from happening.

The two companies say the FTC’s decision is based on a flawed analysis and they plan to challenge it.

“This merger creates an unparalleled opportunity to better serve customers of Staples and Office Depot,” Ron Sargent, chairman and CEO of Staples, said in a press release. “The combined company would generate significant savings, and we’re committed to investing savings in lower prices for all customers. We’ll also use the savings to continue to invest in our people, technology and customer service.”

The companies say the FTC is underestimating the strength of their competition, including online retailers.