Vince Cable launched a staunch defence of Britain's membership of the European Union tonight as he announced the next phase of a Government review into the impact of the single market.
The Lib Dem Business Secretary called on businesses, academics and other member states to submit evidence on the impact of the trading relationship, which is being looked at as part of a "comprehensive audit" of how all European Union powers hit the UK.
The investigation, which reaches across all government departments, was launched earlier this year by Foreign Secretary William Hague, who described it as a "necessary and positive part of reforming Europe".
Mr Cable, a long-standing pro-European, insisted the single market was a "success story" and warned Eurosceptics that Britain would still be bound by most EU laws if it wanted to continue trade links outside the EU.
In a speech at Chatham House in London, he said: "Some argue that Britain could have the benefits of the single market without the wider obligations of EU membership, including the budget, by being members of the European Economic Area like Norway.
"But as a non-member the UK, like Norway, would still be obliged to adopt the vast majority of the EU's rules without any say over them whatsoever.
"Other non-members like Switzerland do not have access to the single market and, where they do have access, they too align Swiss law with EU law over which they have no influence.
"Moreover, the future of the single market is now being subsumed in the wider debate about the Eurozone - which is, of course, a deepening of the single market by removing the exchange rate risk. The British position is that it is possible to have the former without the latter.
"I believe that the UK must lead this debate and our interventions should be based on thorough analysis, constructive and active."
He added: "This debate about EU reform is however not an academic one about how to construct a new Union from scratch. When the UK joined the EU it did not join someone else's club. We have helped to shape it, reform it and refocus it, so that it prioritises those matters where it adds real value."
Mr Cable also used the speech to warn against Scottish independence, arguing that it would break up an even more successful single market.
"The free flow of goods and services has enriched the UK as a whole," he said. "But with the forthcoming referendum on independence this could be under threat.
"Currently, over half of Scotland's total exports are with the rest of the UK. If Scotland becomes independent, the most likely scenario is that it will have to apply to join the EU as a new Member State. A Yes vote will not mean business as usual for Scotland."