Cabinet secretary, Number 10 Downing Street (New entry)

Mr Heywood has always kept a low profile, while making himself indispensable to successive prime ministers. His dramatic entry into the top ranks of the HSJ100 is explained by the very personal role he has taken, and continues to take, as troubleshooter on health policy.

Apart from a few years at Morgan Stanley, Mr Heywood has been a civil servant at the Treasury and Number 10. Much of this has been as a private secretary, the curious role that combines business management, policy advice and political fixing, specifically for your minister. Some would say that, although Mr Heywood has been promoted to Number 10’s permanent and now cabinet secretary, he is essentially carrying out the same role at a higher level.

That prime ministers value him, however, is beyond question. Mr Heywood entered Number 10 to work for Tony Blair and was prized for his ability to get Whitehall to do Number 10’s bidding and his reforming zeal, very untypical in a senior civil servant.

Although in many ways the civil service found the transition from Blair to Brown more difficult than a change of government, Mr Heywood returned to provide leadership to a Downing Street that was, at times, dysfunctional.

Moving seamlessly to support Cameron, he has worked to tackle many policy areas such as student finance that few thought the Conservatives and Liberal Democrats could agree on.

The severely rough ride that health policy is experiencing has seen Number 10 put the DH into “special measures”, with Mr Heywood exerting a firm grip. His great skill is that, as he releases the pressure over time, the department is more than likely to thank him for helping it through a difficult period.