Lord Adonis became part of the New Labour inner circle by "chance".
Speaking to The House Magazine, he said he found himself in Number 10 due to his friendship with David Miliband who was then director of policy for Tony Blair.
Adonis served in the prime minister's policy unit from 1998 until 2005, and as head of policy between 2001 and 2003.
He left Downing Street in 2005 and took a seat in the Lords. He was then appointed a parliamentary under-secretary of state in the department for education.
His steady rise through the ministerial ranks continued under Gordon Brown when was appointed secretary of state for transport in 2009, having requested a move to the department in 2008 as a junior minister.
"I was absolutely astonished to become the secretary of state within a year," he said.
Lord Adonis joined the SDP shortly after turning 18, and maintains that while he may have switched parties, his political views have remained constant.
"I was a modernising social democrat then, and I am a modernising social democrat now," he said.
He explains that when Tony Blair succeeded in abolishing Clause IV there was no longer any ideological separation between "modernising social democrats who were Liberal Democrats and social democrats who were in the Labour Party".
And he speaks of his admiration for his "close friend" Roy Jenkins, describing himself as a 'Jenkinsite'.
"Most people in the centre tend to be wishy-washy and don’t tend to challenge the status quo," he said.
"But Roy showed it is possible to be politically moderate, commanding the respect of both sides in politics, while also carrying through bold progressive reforms – including, in his case, the legalisation of abortion and homosexuality."
Expressing support for a fully elected upper chamber, the transport secretary revealed he would be keen to remain in parliament if his appointed position were to be dissolved.
"If the current House of Lords ended and there was an elected second chamber, then I would need to make a choice about standing for Parliament as a peer or an MP," he said.
"I would be keen to do either."
Also in this weeks The House Magazine, Sam Macrory examines the choice to be made on electoral reform, Andrew Evans looks at an effective reduction in Ulster MPs' salaries and Prof Paul Whiteley studies the impact the Iraq inquiry will have on the general election.
Dods Parliamentary Communications Ltd