Britain's biggest review of its membership of the European Union in 40 years found evidence it had boosted economic growth and helped consumers, but also highlighted the need to keep control of its own tax policy, a government report said on Monday. The first six of 32 reports on Britain's EU ties will form the basis of Prime Minister David Cameron's renegotiation of the country's role in Europe before an in/out referendum he has promised to hold before the end of 2017. "For the first time, these reports bring together in one place evidence from across the spectrum to provide an accurate and detailed picture of the impact that the European Union has on our everyday lives," Foreign Secretary William Hague said. "Some cases highlight the importance of maintaining national sovereignty in areas like direct taxation," the government added in a statement. "Other examples illustrate other areas where EU action has brought benefits to UK consumers and facilitated economic growth - for example, the role that the single market has played in bringing down the price of air  transport and increasing the number of air routes in the EU." The government has described the review as "the most extensive analysis of the impact of EU membership on the UK ever undertaken". It will publish 32 reports between now and 2014. The first set looked at the European single market, taxation, foreign policy, overseas aid, health and animal welfare.