Minnesota Gov. Tim Walz, the Democratic vice presidential nominee, needled former President Donald Trump on Thursday for not holding any campaign events in honor of Labor Day, the 130-year-old holiday recognizing the American labor movement.

“It doesn’t surprise me that Donald Trump did not do a damn thing on Labor Day,” Walz said of the GOP nominee at an Erie, Pennsylvania, rally. “He took the day off, which — he should thank organized labor for that day off.”

Harris and Walz blitzed through Michigan and Wisconsin on Monday’s holiday to campaign before labor groups.

“If I were him, I would be hiding down in Mar-A-Lago, too,” Walz continued. “I wouldn’t want to face working people. I wouldn’t want to look them in the eye and tell them why their work doesn’t matter, why it should be harder to unionize, why he and his folks have undermined middle America.”

Walz and Vice President Kamala Harris, the Democratic presidential nominee, have been hitting Trump hard on his record with labor unions. Earlier this week, their campaign called Trump “one of the most anti-worker and anti-union presidents in history – shipping jobs overseas and lining the pockets of the super wealthy and big corporations at the expense of the middle class.”

The AFL-CIO, the country’s largest federation of unions, has slammed Trump as anti-worker, saying he “waged an assault” on the rights of unionized federal government workers; put union-busing lawyers on the National Labor Relations Board; and has opposed increases to the federal minimum wage.

Both parties are working hard to court union endorsements. Trump recently pitched the the International Brotherhood of Teamsters, one of the largest unions in the world with more than a million members, and Harris plans to hold a similar roundtable with its leaders later this month. The union endorsed President Joe Biden in 2020 and former Secretary of State Hillary Clinton in 2016.

Trump did post on social media in recognition of Labor Day, touting his administration’s passage of the 2020 free trade agreement between the U.S., Canada and Mexico and job training programs. But most of his post was an attack on Harris.

“Under Comrade Kamala Harris, all Americans are suffering during this Holiday weekend — High Gas Prices, Transportation Costs are up, and Grocery Prices are through the roof,” Trump wrote. “We can’t keep living under this weak and failed ‘Leadership.’”