Ms Harman had been under pressure over her decision to send her son to a selective grammar school, but more than half of Labour MPs voted for her, in what a spokesman for the Labour leader described as "an important test of authority".
Mr Blair exerted that authority by announcing a review of discipline among Labour MPs, designed to crack down on what one party official described as "rent-a-gob" dissidents. He is also expected to ignore overwhelming votes for Margaret Beckett, Ann Taylor and Clare Short in what was described as a "limited" reshuffle.
Speculation that Ms Short might be moved from her post as transport spokeswoman was increased last night when she walked out of a television interview when asked if she supported the Tube strike. But within hours she issued a statement backing the leadership line and opposing the strike. Any move to sideline Ms Short would be resented by Labour MPs, who admire her blunt left-wing conviction politics.
Ms Harman came last of the 19 elected, but a substantial 55 votes ahead of her left-wing challenger Ann Clwyd, sacked by Mr Blair last year for missing Commons votes.
A spokesman said Mr Blair and deputy leader John Prescott expected all MPs to focus from now on on attacking the Tories and promoting Labour's New Life for Britain manifesto.
The review of parliamentary discipline is aimed at left-wingers Alan Simpson, Diane Abbott and Ken Livingstone, whose allegations of manipulation in the poll infuriated Mr Blair.
Apart from Ms Harman, the chief loser in the poll was shadow Chancellor Gordon Brown, who slipped from third to 14th place. Mr Brown's plan to review child benefit for 16-18-year-olds came under attack at the Blackpool conference.
A further 18 motions demand increases in the basic state pension in line with earnings - published last night after they were leaked to Tory Central Office.Reuse content