As President of the Selsdon Group, a free-market lobby within the Conservative Party, he was closely aligned with Margaret Thatcher, and became one of her Ministers of State at the Foreign and Commonwealth Office in 1979.
As Secretary of State for Transport, Ridley performed a key function in building up coal stocks in advance of the 1984–85 miners' strike, which helped the government to defeat the National Union of Mineworkers (NUM).
As Secretary of State for the Environment, Ridley opposed a low-cost housing development near his own property, earning him the title of "NIMBY" ("Not in My Back Yard").
[2] Ridley held a national service commission as a lieutenant in the 1st Battalion of The Loyal Regiment in 1947 and was later a Territorial Army captain in the Northumberland Hussars Yeomanry.
Ridley held a secret, informal meeting with his Argentine opposite number Carlos Cavandoli in September 1980, and the two sides broadly agreed to a "leaseback" arrangement whereby nominal sovereignty would be given to Argentina but British administration would be maintained for a fixed number of years, likely 99, until the final handover, as well as co-operating on the Islands' economic development and exploitation of fish and potential oil resources.
The meeting took place at a village hotel ten miles outside Geneva, Switzerland, under the pretext of a holiday for Ridley and his wife, so as to avoid Parliamentary and media accusations of a sell-out.
[9] Likewise, Parliament gave the proposals a hostile reception, pointing out that British people should not be transferred, against their wishes, to the control of an Argentine military junta which had committed multiple human rights violations.
His fierce political opponent Tam Dalyell believed he was right and that but for Ridley's "confrontational style", "off-handed and offensive disdain" which upset both the islanders and the House of Commons, this policy could have avoided the war.
Following the 1983 election, Ridley, always regarded by Margaret Thatcher as "one of us", was a beneficiary of her move to cull the Tory wets and joined her cabinet as Secretary of State for Transport.
In that role he played a major part in making preparations for a potential loss of coal supplies, which proved an important factor in deciding the outcome of the miners' strike.
By the time that the miners did strike, from early March 1984, considerable efforts had been made in ensuring the availability of stockpiled coal at power stations, non-unionised transport workers and oil-fired generation plant.
As Secretary of State for the Environment from 1986 to 1989, he is credited with popularising the phrase NIMBY or Not in My Back Yard to describe those who instinctively opposed any local building development.
[11] More importantly, he was the Cabinet Minister responsible for the introduction of the 'Poll tax' (formally known as the Community Charge), a policy that brought a standing ovation at the Conservative Party conference at which it was announced, and riots across the country when it was implemented.
The interview was illustrated with a cartoon depicting Ridley running away having added a Hitler moustache to a poster of the German Chancellor Helmut Kohl.
Some commentators point to Ridley's resignation, its manner, and the European issue at its core, as leading indicators for the next decade of Conservative Party politics.
[19]Ridley was also secretary of the Canning Club, a councillor on Castle Ward Rural District Council and a member of the executive committee of the National Trust.