Prime Minister Junichiro Koizumi tried Thursday to persuade two octogenarian former prime ministers to retire from politics because of their age, effecting a quiet exit in the case of Kiichi Miyazawa but running up against a brick wall in the shape of Yasuhiro Nakasone.

Political observers said Koizumi's failure to persuade both men to quit may be viewed by voters as a leadership shortcoming.

Nakasone, 85, and Miyazawa, 84, had both voiced plans to run in the Nov. 9 general election for the House of Representatives on the Liberal Democratic Party's proportional representation ticket -- effectively defying a new LDP rule banning people 73 or older from running in that segment of the vote.