Youngest hospital boss who is earning £155k aged just 32... and the NHS chief (52) who happens to be her fiancé

The chief executive of the NHS faces questions over his relationship with one of the country's youngest hospital bosses - who is 20 years his junior.

David Nicholson, 52, who is in charge of managing the Health Service in England and Wales, has announced he is to marry Sarah-Jane Marsh, 32, next year.

Miss Marsh was appointed to the £155,000-a-year post at scandal-hit Birmingham Children's Hospital in June this year. She is thought to be the youngest-ever holder of a chief executive position.

She was given the role despite the fact Government health watchdogs had criticised management at the trust while she was previously in charge of day-to-day operations.

In 2002, Miss Marsh was selected for a six-month placement in Mr Nicholson's office when he was in a senior health role for the Midlands and the East of England.

She was one of a number of graduate trainees taken on by the NHS every year and her success story appears prominently on the management scheme's promotional website.

Since her time working with Mr Nicholson, she has enjoyed a rapid ascent of the management ranks, taking on two senior roles in Walsall before securing a chief operating officer job at Birmingham Children's Hospital in December 2007.

She became interim chief executive at the trust in March this year. On each occasion, Mr Nicholson has been named as a referee on her application. However, the Department of Health (DoH) says he only provided a reference for her first position in Walsall.

It is unclear when the pair's relationship began but Mr Nicholson formally informed the Permanent Secretary to the DoH, Sir Hugh Taylor, of his engagement to Miss Marsh at the start of September.

DoH officials would not confirm whether Mr Nicholson had previously mentioned the relationship or when it started.

Mr Nicholson is thought to be divorced with two grown-up sons. In an interview given in June this year, the interviewer wrote: 'His family, who live in Harrogate, must see virtually nothing of him.'