President Trump may be in for a star-spangled bungle — if his Chinese-made re-election banners are hit by his punitive tariffs.

The “Trump 2020” red, white and blue flags — emblazoned with his next campaign motto, “Keep America Great!” — are ready to be shipped from the Jiahao Flag Co. in Anhui province and may be slammed by the president’s own measures, according to Reuters.

Since March, the factory has churned out 90,000 of the beach towel-size flags, an unusually large number for the normally slow season, said manager Yao Yuanyuan, who believes the looming US-China trade war is the reason.

“It’s closely related,” she said. “They are preparing in advance, they are taking advantage of the fact that the tariffs haven’t gone up yet, with lower prices now.”

On Tuesday, Trump declared on Twitter that “tariffs are the greatest!”

“Either a country which has treated the United States unfairly on Trade negotiates a fair deal, or it gets hit with Tariffs,” he wrote. “It’s as simple as that – and everybody’s talking! Remember, we are the ‘piggy bank’ that’s being robbed. All will be Great!”

His administration has levied tariffs on $34 billion worth of goods from China.

After Beijing retaliated in kind, Washington announced levies on an additional $200 billion worth of products and threatened more, targeting potentially all of China’s exports to the US — including Trump’s $1-apiece re-election flags.

Yao’s factory has been making his banners since his tag line as a candidate was “Make America Great Again.”

“Sales have been great ever since 2015,” she said.

But “if he continues to demand tariff increases as he has been, or if he continues to agree with those who are against China, I definitely would not be able to accept (more orders),” she said.

“Everyone can have a patriotic heart, but this won’t improve his economy, and instead it could make us Chinese just shoot ourselves in the foot.”

However, factory worker Sun Lijun is not exactly waving the white flag.

“I know that Trump’s tariffs targeting China will have some effect, but we’re not worried at all, since we’re producing foreign flags every single day,” she said.

With Post wires