Every step he has taken in his thirty-six-year life has brought him money and power. The son of an RAF officer, he was a public schoolboy, president of the Oxford Union and a Kennedy scholar at Harvard. But his education did not prevent him appealing to the vulgar instincts of the Essex-man Conservative Party.
'I've been a Conservative since my balls dropped,' he proclaimed on one occasion. On another, he said that he was worried that the welfare state was creating a 'thuggish underclass'.
Despite his language, many Conservatives regarded him as a rising star and an intellectual force to be reckoned with. Shortly after arriving in Parliament he published a paper calling for an independent Bank of England and an end to mortgage subsidies.
'He is bright, young and dynamic,' said David Evans, vice- chairman of the Conservative backbench 1922 Committee.
Perhaps it is not surprising that money rather than sex led to Duncan's resignation. After leaving Oxford, he worked for Shell and then joined the oil trading company owned by Marc Rich until 1988.
Rich lives in Switzerland, which has no extradition treaty with the United States. If he were ever to leave, however, the US authorities would have him arrested and deported to face charges of tax evasion, fraud and racketeering.
Even though Rich cannot visit Britain without being picked up by the police, the Government gave him a licence to trade in privatised electricity. When questioned about Rich last year, Duncan maintained that the charges were less serious than they sounded. 'It is silly that the US has allowed it to linger on,' he said.
After leaving Rich, Duncan became a freelance oil trader and adviser on oil to the Pakistani government. He is said to have made a lot of money during the Gulf war. But he always had an eye on a political career. At Oxford, Duncan was on the right when Thatcherism was unfashionable. He became a close friend of William Hague, another young Oxford Conservative, who had wowed the party conference as a 16-year-old with his passionate support for Margaret Thatcher.
In 1988, Duncan got his chance to impress the Conservative leadership by delivering an enthusiastic speech to party conference.' Do we support the Government?' he cried, and answering his own question, replied: 'We do] We do] We do]'
Unsurprisingly, his speech drew praise from Nigel Lawson, then Chancellor of the Exchequer, and he was selected as candidate for Rutland and Melton, a safe Tory seat.
But his most astute move came before he won Rutland in the 1992 general election. During the leadership contest after the fall of Margaret Thatcher, Duncan put his pounds 250,000 home in Gayfere Street, Westminster, at the disposal of the Major campaign. Ten phone lines were already installed so he could trade in oil from home.
Although he fell out with the Major team, when he proved to be a Euro-sceptic during the Maastricht debate, he was rewarded for his support two weeks ago when he was put on the first rung of the ladder to ministerial office by being made Parliamentary Private Secretary to Brian Mawhinney, the health minister.
On Friday night, when the story about his house purchases was being printed in the Sun, he was appearing on a pre-recorded chat show arguing with Clare Short, Labour MP for Birmingham Ladywood, about political correctness.
Asked by Ms Short to justify his claim that political correctness was oppressive, he waved a newspaper cutting which claimed that playgroups had been told to cancel Christmas festivities because they were offensive to children from non-Christian backgrounds. The cutting was from the Sun.
Inside Story, pages 14 and 15
Leading article, page 18