Sir Michael, 52, has given 12 years of loyal service to the royals, reportedly attracting the sobriquet "the axe man" for his success at shoring up the royals' finances.

He made this reputation during his time as Keeper of the Privy Purse and Treasurer to the Queen.

Sir Michael has worked for Charles and the Queen

The Eton and Oxford educated accountant was seen as a moderniser in the royal household and advised the Queen to pay tax on her private income from 1993.

His tough financial stance at Buckingham Palace is thought to have saved taxpayers �37m-a-year.

It was he who hinted that the Royal Train, which costs �35,000 every time it is used, may have reached the end of the line.

He worked for the Queen for more than a decade, until earlier this year, when he became Prince Charles's private secretary, replacing Stephen Lamport.

High earner

Sir Michael's credentials are impeccable and accountancy is in the blood.

His father was a Privy Purse auditor, as was his great-grandfather William Barclay Peat, who was a founding partner of the accountancy firm Peat Marwick, now KPMG, where Sir Michael was previously a partner.

He spent about 20 years in the family business, until joining the royal household in 1990.

He was director of Finance and Property Services, HM Household, from 1990-96 and Keeper of the Privy Purse from 1996-2002.

He is said to be the most expensive member of Prince Charles's staff.

When he left Buckingham Palace, his salary was reportedly �172,000 - of which �47,000 was reimbursed to the Property Services as rent for his apartment at Kensington Palace.

It is likely his earnings have increased since joining St James's Palace.

In his prestigious role as Prince Charles's private secretary, he oversees his royal employer's public and private engagements.

Sir Michael, who lists history, sport and literature among his interests, has a son and two daughters by his wife Deborah, whom he married in 1976.