Outgoing Japanese Prime Minister Yasuo Fukuda bows at the ruling Liberal Democratic Party's (LDP) parliamentarian meeting at the party's headquarters in Tokyo September 3, 2008.

Outgoing Japanese Prime Minister Yasuo Fukuda was unpopular with voters but T-shirts printed with his huffy parting shot are now a hit.

At a nationally televised news conference where he abruptly announced his resignation on Monday, Fukuda was criticized by a reporter for not having had his heart in his job.

"I can see myself objectively. I'm not like you," he snapped back.

The flash of anger took many voters by surprise because Fukuda had kept his testy temperament under wraps as leader.

The comment, the talk of Internet chat rooms, has spawned T-shirts, mugs and even baby romper suits printed with the words: "I'm not like you".

"We can't keep up with orders," said Tomohiro Miyake, president of online shop Club T, who was too busy to count sales, but added that the T-shirt was about to become his company's best-selling ever.

Some voters thought Fukuda sounded arrogant, while others said the leader, who reportedly had not told his wife about quitting, had merely showed his human side.

"It was his last news conference, so he let his emotions slip," said Hiroshi Fukada, 56, a public servant. "Even I feel like saying 'I'm not like you' to people sometimes."

One mobile phone website offers the chance for users to create their own variant of the phrase.

"I like my fried eggs with soy sauce. I'm not like you," said one.