A campaigning Mayor Bill de Blasio called for a boycott of Walmart Saturday in the wake of last week’s mass shooting in El Paso — and also took aim at President Trump and his “tiny little hands.”

“I’ve got a little message for President Trump,” he said to polite applause at an Iowa gun-control forum Saturday. “Mr. President, it’s not Hollywood. It’s not video games … It’s the guns that are the problem.”

“Take those tiny little hands of yours, pick up the phone, call Mitch McConnell, and say the Senate has to vote for gun safety measures right now,” de Blasio continued.

Hizzoner, making his yet another visit to the Hawkeye State since announcing his quixotic White House bid in May, pushed advocates at an Everytown for Gun Safety event in Des Moines to boycott big-box behemoth Walmart to get their message across.

“It’s time to boycott Walmart,” he said. “It’s time to stop putting money in the hands of a company that puts out on the streets that kill innocent people.”

“Right now they have to feel our wrath for change to happen,” he added.

After the event, de Blasio expanded on the boycott call.

“Walmart has such a horrible history,” he told reporters. “You’re talking about a massive amount of guns that are available. They have to change.

“I’ve watched Walmart on labor issues, environmental issues, they only respond to pressure. So let’s give them pressure.”

The all-day event, hastily organized in the wake of last week’s mass shootings in Texas and Ohio, attracted about 700 activists from around the country – but scores flooded out of the event after the Democrats’ top-tier contenders, including Vice President Joe Biden, Sen. Elizabeth Warren, and Sen. Kamala Harris, had taken their turn.

De Blasio’s three-day junket peaks with a Sunday visit to the Iowa State Fair.