As a backbencher, Heseltine became very critical of Thatcher's government and refused to support the Poll Tax in 1989. In November 1990, Heseltine challenged Thatcher for Conservative Party leadership and this led to Thatcher resigning, but Heseltine did not get to become party leader. New Conservative Prime Minister John Major made Heseltine Secretary of State for the Environment (1990-1992), President of the Board of Trade (1992-1995) and Deputy Prime Minister (1995-1997).