At peak production 15% of UK supply came from the two main fields. As of 2006 Centrica reckoned there was about 1.2tcf of economic gas remaining in them, and they planned to operate the fields for another 10–15 years. In June 2011 they announced the South Morecambe field would be suspended as a result of tax increases in the 2011 Budget which meant South Morecambe would be paying a rate of 81% tax; North Morecambe and Rivers would continue in production as they are taxed at 62%. Production resumed from the South Morecambe field in July 2011.