LONDON (AP) — The CEO of British supermarket chain Sainsbury’s has apologized after being caught on camera singing ‘We’re in the Money’ following the purchase of Walmart’s British unit, Asda.

Mike Coupe was preparing for an ITV interview to discuss the $10 billion deal when caught on microphone singing a song from the musical ’42nd Street,’ which is based on a movie made during the Great Depression.

As he composed himself for the interview, Coupe sang “we’re in the money, the sky is sunny, let’s lend it, spend it, send it rolling along.” He later described it as “an unguarded moment” on a stressful day.

“It was an unfortunate choice of song, from the musical 42nd Street, which I saw last year, and I apologize if I have offended anyone,” he said.

The Unite union, which is worried about job losses resulting from the takeover, posted a video of Coupe’s song on its Twitter feed.

“What’s his true motive for the merger? Sainsbury’s boss sings ‘We’re in the Money’ before TV interview,” Unite tweeted.

The value of Coupe’s 1.28 million shares in Sainsbury’s rose over half a million pounds ($750,000) Monday after the deal’s announcement.