Obituary Sir Lenox Hewitt was a mandarin respected and feared by leaders

What's the vacant seat for? asked a colleague.

"Files," said Hewitt.

That was not always so. Hewitt enjoyed being able to stretch out without being captive of a chatty stranger, or, probably worse, a colleague. But down in the hold - or on the spare seat - were the most important files of his department. They were always near. He who had the files had the power.

Hewitt also knew that he who crafted the minute, or drafted the report, controlled the agenda. Early in his bureaucratic career, Hewitt had mastered shorthand. Only a brave public servant - or secretary or minister - would challenge the record. The more so because Hewitt could often be very rude and abrupt.

He used extravagant (if never profane) language when aroused, and was a bad man to cross. He was said at one time to be the most unpopular man in Canberra. Some of his colleagues thought him a usurper, occupying a job that by rights belonged to Sir John Bunting. Bunting had been appointed secretary by Sir Robert Menzies, and had served Sir Harold Holt and Sir John McEwen.

Gorton, who became prime minister in 1968, was like Hewitt. A bit of an outsider. A loner by temperament, who did not want to be "managed" by the old guard. Neither team men, unless they were captain, and then demanding absolute obedience.

Hewitt was to become best known for two partnerships with politicians. After Gorton it was to be with Rex "Strangler" Connor, Gough Whitlam's minister for resources and energy. Gorton and Connor, of opposite parties, had similar temperaments, and were nationalist by outlook. Each had intense personal relationships with Hewitt. They saw themselves as working against powerful and entrenched foes. Hewitt's loyalty was professional but total while the minister was the minister.

The partnerships were to be undone by their secretive and unyielding personalities and styles, and their willingness to go down unconventional paths.

Sir Lenox, knighted in 1971, was a public champion of blunt and independent, but private advice. He was to claim later that he had often counselled restraint when none was shown, and attack when retreat was to occur. His recollections were sometimes self-serving, rarely rueful. One suspects his ministers were getting too much encouragement and back up, and not enough warnings about caution.

Gorton was minister for education when Hewitt, a former deputy secretary of Treasury became chairman of the Commonwealth Universities Commission. Gorton liked his style. They were both combative, suspicious of colleagues, and very focused, confident both of their command of the facts and their authority. They often lacked patience, and couldn't be bothered with tact, wooing and cajoling or compromise. Each was willing to tread on toes. Each had great passion for their objectives. If they could be tough, each also had great, if self-deprecating charm.

Gorton got rid of Bunting as chief adviser by abolishing PM&C and creating two "new" departments: PMs, to be headed by Hewitt and a tiny Cabinet department under Bunting.

Hewitt began his career as a BHP trainee before World War II, acquired a degree in economics, and worked with Douglas Copeland on price controls before joining Treasury. He was later to become a critic of this department. This was not, he said, because of any change of philosophy. It was a realisation, from a new vantage as a "client" that it was not, or not any longer, as enlightened as he had once thought. Many other Treasury-trained officer has had a similar conversion in putting philosophy into practice.

Hewitt, Gorton, and Gorton's private secretary, Ainslie Giotto became a tight knit team, intensely loyal to each other. All departmental advice was funnelled through Hewitt, whose office was in Parliament House. It resembled the modern-day prime minister's office, even if it was staffed by professionals rather than partisan minders. To old functions of "co-ordinating" government, it built the ability to second-guess other departments on almost every issue of policy.

Gorton often bypassed Cabinet and imposed policy from on high without consultation. He was impatient with process. The autocratic style of each in the triangle saw some cut through - but also made Gorton, and Hewitt powerful enemies.

Gorton was to be succeeded by Billy McMahon, a man for whom Hewitt had lasting contempt. Bunting came back, PM&C was re-created, and Hewitt went into temporary exile as head of a new department of Aborigines, environment and the arts, lowest on the scrap-heap.

Under Gough Whitlam, Hewitt became head of resources and energy. He and Connor forced big price increases for iron ore from the Japanese. They did not want Australia as a vast quarry selling everything at bargain-basement prices. Both wanted Australia to value-add instead of merely exporting raw materials. They were ready to leave resources in the ground until there were higher prices.

After the first oil shock of 1974, Middle Eastern countries were awash with "petro"-dollars. Would-be middle men claimed they had access to newly rich sheikhs with money to invest. To Labor, Treasury seemed fuddy-duddy, preferring to borrow on conventional finance markets in London and New York.

The conman Tirath Khemlani was introduced to Connor, who was given authority to negotiate a loan, to the horror of Treasury.

The dreams of Connor, Whitlam and even Hewitt about what to do with the $4 billion said to be on offer were noble and visionary. Connor wanted to buy back the farm. To join Australians with a gas pipeline. To establish national infrastructure. Later Hewitt was to insist he knew and advised his minister the irregular loan-raising attempts to have been a scam. That seemed odd given his characteristic total loyalty to Connor and a denialist and aggressive approach to criticism at the time.

Eventually the scandals brought down Connor and treasurer Jim Cairns, and ultimately the Whitlam government. By then, Hewitt had nimbly jumped aside, to become chairman of Qantas. Some foolish newspapers said he had been "sacked'. Hewitt sued for an imputation of impropriety, and got many thousands in damages from multiple papers. Not from The Canberra Times, aware of the risks of using such words when public servants were moved on.

Hewitt ever after denied that the secretive and combative style of Connor and himself contributed to the disaster.

"That's just latrine gossip," he told Gay Davidson in 1985. "You know one of the curses of Canberra is the inability of people to mind their own business, and leave others to get on with their responsibilities."

Qantas, then only an international airline, was very successful under Hewitt's leadership. But the style remained. He was often imperious to staff. It was said in Canberra that when he travelled, which was often and usually in great style, Qantas had to put on an officer to be sure his baggage arrived at the right destination. Otherwise, it had a habit of arriving in Ulan Bator, or Dar es Salaam.

After retirement, he remained active on government boards, state and federal, including NSW rail and the Snowy Mountain Engineering Corporation, the NSW Judicial Commission and the Atomic Energy Commission.

He could be roused to defend old notions of the public service vocation again modern "reforms" - not least the loss of tenure for secretaries, the disappearance of the concept of office, and the corrosive effect of the modern focus on "responsiveness". He was critical of the minder system. He was to outlive almost all of his enemies, though his causes survive.

His wife, Hope (nee Tillyard) was a Canberra academic, poet, member of the Commonwealth Literary Board and Canberra Times reviewer. They married in 1942; she died in 2011. He had four children, Andrew, Patricia (who was to become a Cabinet minister in the Blair Labour government in Britain), Antonia (who died in 1990) and Hilary.