<Table> <Tr> <Td> "</Td> <Td> Resolved, That this House approves Her Majesty's Government's decision of principle to join the European Communities on the basis of the arrangements which have been negotiated . </Td> <Td>" </Td> </Tr> </Table> <Tr> <Td> "</Td> <Td> Resolved, That this House approves Her Majesty's Government's decision of principle to join the European Communities on the basis of the arrangements which have been negotiated . </Td> <Td>" </Td> </Tr> <P> No referendum was held when Britain agreed to an accession treaty on 22 January 1972 or when the European Communities Act 1972 went through the legislative process, on the grounds that to hold one would be unconstitutional . The United Kingdom joined the European Communities on 1 January 1973, along with Denmark and the Republic of Ireland . The EC would later become the European Union . </P> <P> Throughout this period, the Labour Party was divided, both on the substantive issue of EC accession and on the question of whether accession ought to be approved by referendum . In 1971 pro-Market figures such as Roy Jenkins, the Deputy Leader of the Labour Party, said a Labour government would have agreed to the terms of accession secured by the Conservatives . However, the National Executive Committee and the Labour Party Conference disapproved of the terms . In April 1972 the anti-EC Conservative MP Neil Marten tabled an amendment to the European Communities Bill, which called for a consultative referendum on entry . Labour had previously opposed a referendum, but the Shadow Cabinet decided to support Marten's amendment . Jenkins resigned as Deputy Leader in opposition to the decision, and many Labour MPs abstained on the division . </P>

What year did england join the common market