Margaret Thatcher tendency to override collegiate opinion, contributed to discontent within her party. Thatcher removed Geoffrey Howe as Foreign Secretary in July 1989 after he and Lawson had forced her to agree to a plan for Britain to join the European Exchange Rate Mechanism (ERM). Britain joined the ERM in October 1990. On 1 November 1990, Howe, by then the last remaining member of Thatcher's original 1979 cabinet, resigned from his position as Deputy Prime Minister, ostensibly over her open hostility to moves towards European Monetary Union. In his resignation speech on 13 November, Howe commented on Thatcher's openly dismissive attitude to
Deputy Prime Minister of the United Kingdom Tyne. William Whitelaw was Margaret Thatcher's "de facto" deputy from 1979–1988, an unofficial position he combined with that of Home Secretary in 1979–1983 and Leader of the House of Lords after 1983. Sir Geoffrey Howe was bestowed the title of Deputy Prime Minister by Thatcher in 1989, on being removed from the post of Foreign Secretary. He resigned as her deputy in 1990, making a resignation speech that is widely thought to have hastened Thatcher's downfall. Thatcher's successor John Major did not appoint a Deputy Prime Minister until 1995, when Michael Heseltine was given the post. John Prescott, who was