The retail chill created on Fifth Avenue by the heavy security and protests surrounding Trump Tower has spread one block east to Madison Avenue, store managers told The Post on Wednesday.

“Some customers are apparently reluctant to come to the area, and cabs seem to be avoiding it as well, traveling north on Park Avenue instead,” said Rob Byrnes, president of the East Midtown Partnership. The threat of protesters crowding the street isn’t helping.

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Last weekend, protesters waving pro-Trump signs and others with “Not My President” signs were diverted off Fifth onto Madison — clashing angrily along the way.

A manager at the Lacoste store at 575 Madison Ave., located behind Trump Tower, called his regular customers to let them know about a special shipment of apparel and was told by many that they didn’t plan to visit the store because of the “security situation.”

The manager estimates that sales are down about 20 percent over the past week compared with a year ago. Even services like Urban Express, which makes deliveries to Lacoste customers’ hotels and apartments, have declined some trips.

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A couple doors down at Les Canebiers, a St. Tropez fashion brand, business also has been affected.

This story originally appeared on NYPost.com.