British Prime Minister David Cameron on Monday said he had "no emotional attachment" to the institutions of the European Union (EU) and wanted to "debunk" the idea that Britain could not survive outside the regional grouping.
Addressing the annual conference of the Confederation of British Industry (CBI), he said he was not satisfied with the status quo and Britain had to renegotiate its deal with Europe, Xinhua news agency reported.
If he gets the changes he wants, Cameron said he will campaign "vigorously" to stay in the EU.
If not, he said he will "rule nothing out".
Cameron said it will be "difficult and hard" but he believed that he can convince the EU's other 27 states to commit to irreversible and legally-binding commitments before the British public go to the polls.