Three Japanese lawmakers have launched their campaigns to lead the ruling party, kicking off the race to succeed Prime Minister Junichiro Koizumi.
The leadership will be decided on 20 September
Chief Cabinet Secretary Shinzo Abe, 51, is the clear front-runner to win the 20 September contest for the Liberal Democratic Party presidency.
The other two contenders are Foreign Minister Taro Aso and Finance Minister Sadakazu Tanigaki.
The holder of this post is almost certain to be made prime minister.
There will be a parliamentary vote for prime minister on 26 September, four days before Mr Koizumi is due to step down.
20 Sept: LDP lawmakers and over one million LDP members elect party president
26 Sept: Party president almost certain to be elected PM by LDP-dominated parliament
30 Sept: Prime Minister Junichiro Koizumi steps down
Mr Abe has a strong lead in opinion polls and appears to have the backing of the majority of LDP lawmakers.
A staunch conservative, he has pledged a robust foreign policy and emphasised his aim of holding a referendum on constitutional revision.
But critics fear the election of Mr Abe, who has backed Mr Koizumi's visits to a controversial war-linked shrine, could lead to further deterioration in ties with China.
"To improve relations with China and South Korea, I believe all sides must make efforts to take steps forward," Mr Abe said as he launched his campaign.
An opinion poll by the Mainichi newspaper showed 55% support for Mr Abe, with Mr Aso and Mr Tanigaki receiving 6% each. Other media estimated that Mr Abe had the backing of about 70% of lawmakers.
But Mr Tanigaki and Mr Aso remained buoyant.
"The LDP is not made up solely of those who agree with the so-called frontrunner," Mr Tanigaki said. "I am prepared to fight to the end."