Amazon has introduced a new feature that markets its private-label brands right before consumers add rival products to their shopping carts.

The Washington Post conducted dozens of product searches and saw offers for a “similar item to consider” featuring an Amazon brand appearing just above the area where shoppers click to add a purchase to their cart.

The boxes reportedly touted lower-priced Amazon versions of everyday items like Glad trash bags, Dr. Scholl’s gel insoles and Energizer batteries.

The retail behemoth, of course, has a huge amount of power over what’s sold on its platform thanks to its data-mining capabilities. That dominance is drawing scrutiny from regulators and lawmakers in America — including Sen. Elizabeth Warren (D-Mass.), who wants to break up Amazon on antitrust grounds.

According to research firm eMarketer, Amazon is expected to account for more than 37 percent of all e-commerce sales in the US this year.

“It’s an ad at exactly the moment the customer is ready to buy,” James Thomson, a former senior manager in business development at Amazon and now a partner at brand consultancy Buy Box Experts, told the Washington Post. “I don’t see how that’s not unfair.”

Amazon defended itself in a statement to the Washington Post, likening the promotion to the way any store would push its own private-label goods.

“Like any retailer we promote our own brands in our stores, which provide high-quality products and great value to customers,” Amazon spokeswoman Nell Rona told the paper. “We also extensively promote products from our selling partners.”

The Washington Post found examples of AmazonBasics being shown to shoppers searching for diapers, coffee pods, beauty products, vitamin supplements, nicotine gum and more.