SINGAPORE Senior Minister Lee Kuan Yew, the former prime minister, who is known for his tough talking and abrupt manner, has admitted that he can be very rude when he has to be. ''If somebody persists on pestering you when you want to be left alone, you will have to tell him to leave,'' he said. ''But I am not unnecessarily rude, I hope. I believe I am a controlled person.'' Mr Lee was talking about Singapore's annual courtesy campaign, which he initiated 15 years ago when he was prime minister, in an interview with The Straits Times. It was suggested to Mr Lee that when he was fighting a political opponent people saw a different side of him. ''Of course, I am not there for him to punch me up,'' he said. ''If you want to punch me up, I'll punch you up. That's part of my job.'' Singapore's latest courtesy campaign has focused on the rudeness of some of its citizens at home and abroad, and in particular their boorishness at buffet tables. Mr Lee said that this might stem from the hardship of the post-war years. In the 1940s people bought as much best-quality rice as possible because they did not know when they would be able to get it again. ''So that probably led to the buffet syndrome where if you see the table there, you grab the food before other people do it,'' he said. He said that having survived that difficult period, Singaporeans should begin to behave differently. Asked whether there was a timetable for Singapore to become a courteous nation, he said it was ''a marathon with no finishing line''. Some Singaporeans have opposed the new courtesy campaign posters, with their examples of rudeness at buffet tables and on trains, saying Singapore should not wash its dirty linen in public. ''We are what we are,'' Mr Lee said. ''Even if we try to suppress information about how our people behave, six million tourists visit us and take away very strong impressions of the kind of people we are.''