Michael Barber is known throughout Whitehall as "Mr Targets". The head of Tony Blair's delivery unit has a legendary capacity to produce bewildering slides showing what progress the Government is making towards hitting its plethora of public-service performance targets.
Mr Barber can become the bane of a minister's life and some departments resent Downing Street's interference in their affairs. But he is only doing the Prime Minister's bidding. The former history teacher and professor of education was poached by Mr Blair from the Department of Education, where as head of its standards and effectiveness unit he devised the literacy and numeracy targets.
He has kept a low public profile since provoking a dispute in 1998 when he told a conference that Christianity had become a minority interest.
But Mr Barber, 47, has been an influential behind-the-scenes figure at the heart of the Government. His unit is relocating to the Treasury, a move seen as strengthening the already powerful grip on public services of Gordon Brown, the Chancellor.
In recent months, there has been a mini-rebellion by some cabinet ministers against the targets system. The number of targets has been reduced from about 300 to 130 and some ministers have begun to abandon "unrealistic" goals they were never going to achieve.
But Mr Barber is unrepentant. Despite the dissent, he insists the Government has never set a bad target, and is convinced the public will see the benefits of the improvements now showing up on his slides and graphs. Some ministers are not so optimistic.