Netherlands-based Nexperia, which is owned by China’s smartphone giant Wingtech, completed the purchase of Wales-based Newport Wafer Fab for an undisclosed amount earlier this week.
However, the deal for a top UK industrial asset has sparked widespread outcry amid increasingly strained relations between London and Beijing and growing scrutiny of Chinese companies’ overseas investments.
It has also attracted scepticism due to a global shortage in semiconductors.
On Tuesday, Johnson’s spokesman told reporters the government had decided it would not be “appropriate to intervene at this time”.
But a day later, during questions from a panel of lawmakers, Johnson himself said the sale would now be probed.
“I have asked the national security adviser to look at it,” he told MPs.
“We have to judge whether the stuff that they are making is of real intellectual…