South Korean President Lee Myung Bak, who passed the halfway point of his five-year term on Aug. 25, hoped to bolster his political foundation with the start of a new Cabinet to be headed by a man who would be the first prime minister in his 40s (47) in 39 years. But his hope was shattered Sunday when his prime minister nominee and two Cabinet minister nominees announced their withdrawal from the approval process in the national parliament.

In July, Mr. Lee overhauled the staff at the Blue House. Among his new aides is Mr. Yim Tae Hee, former labor minister, who became chief of staff. The same month, the ruling Grand National Party elected Mr. Ahn Sang Soo, a loyalist of Mr. Lee, new party chairman. On Aug. 8, Mr. Lee named Kim Tae Ho, former governor of South Gyeonsang province, as new prime minister and replaced seven other ministers in the biggest Cabinet reshuffle since he came to power in later February 2008.

These changes represented Mr. Lee's attempt to shore up his administration for the second half of his term. Although the ruling party won five of eight parliamentary by-elections on July 28, it had suffered a crushing defeat in the June 2 local elections. Mr. Lee's party, which had held 11 of the 16 mayoral and gubernatorial posts, won only six while the opposition Democratic Party won seven of the 16 races.