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
Margaret Thatcher as a possible future Prime Minister. The description helped Thatcher meet with prominent persons during a busy itinerary focused on economic issues, including Paul Samuelson, Walt Rostow, Pierre-Paul Schweitzer and Nelson Rockefeller. Following the visit, Heath appointed Thatcher to the Shadow Cabinet as Fuel and Power spokesman. Prior to the 1970 general election, she was promoted to Shadow Transport spokesman and later to Education. In 1968 Enoch Powell delivered his "Rivers of Blood" speech in which he strongly criticised Commonwealth immigration to the United Kingdom and the then-proposed Race Relations Bill. When Heath telephoned Thatcher to inform her that he