The Democratic Party of Japan will seek to "substantially extend" the Diet session and pass key legislation dealing with the aftermath of the March 11 calamity, DPJ Secretary General Katsuya Okada said Wednesday.

But the Liberal Democratic Party has said it opposes stretching the session beyond its scheduled June 22 end, saying Prime Minister Naoto Kan only wants to "prolong the life" of his leadership.

During a speech in Kawasaki at the national conference of the Japan Postal Group Union, Okada stressed that an extension wouldn't automatically mean Kan would remain at the helm throughout the session.