After the failure of the 1969 constitutional referendum, de Gaulle resigned and Pompidou was elected president of France. In the general election of 15 June 1969, he defeated the centrist President of the Senate and Acting President Alain Poher by a wide margin (57%–42%). Though a Gaullist, Pompidou was more pragmatic than de Gaulle, notably facilitating the accession of the United Kingdom to the European Community on 1 January 1973. He embarked on an industrialisation plan and initiated the Arianespace project, as well as the TGV project, and furthered the French civilian nuclear programme. He was sceptical about the "New Society" programme of his prime minister, Jacques Chaban-Delmas. In 1972, he replaced Chaban-Delmas with Pierre Messmer, a more conservative Gaullist. While the left-wing opposition organised itself and proposed a Common Programme before the 1973 legislative election, Pompidou widened his presidential majority by including Centrist pro-European parties. In addition, he paid special attention to regional and local needs in order to strengthen his political party, the UDR (Union des Democrates pour la Ve République), which he made a central and lasting force in the Gaullist movement.