Britain's exit from the European Union would boost the economy by £1.3 billion, according to a senior trade diplomat.
Iain Mansfield claims that reduced red tape combined with increased trade to the USA and emerging markets in Asia and Latin America would help the UK secure a "positive economic future".
The director of trade and investment at the British Embassy in Manila drew up a blueprint for Britain's withdrawal from the EU for the Institute of Economic Affairs "Brexit" - British exit" - competition, scooping the top prize of £82,000.
Mr Mansfield, who previously worked for the Department of Business, Innovation and Skills, said an independent Britain should negotiate membership of the European Free Trade Association (Efta) in an effort to keep zero trade tariffs but remain outside the European Economic Area to avoid being hit by regulation from Brussels.
Overall, leaving the EU is likely to boost gross domestic product by £1.3bn, according to the report.
Mansfield, who lives in the Philippines with his wife and son, said: "At the core of Brexit policy should be an embrace of openness: openness to global trade, openness to worldwide diplomatic partners, and openness to international business and investment. Leaving the EU would involve an inevitable trade-off between access to the single market and independence from European regulations, legislation, and budgetary contributions.
"I take no position on whether a Brexit is desirable, but in the event of such a decision by the people of Britain, my paper sets out a course of action that would maximise the potential for an open, prosperous and globally engaged UK."
The report, A Blueprint For Britain: Openness Not Isolation, calls for the working time directive, several agricultural regulations, binding renewable energy targets, and health and safety laws imposed on businesses operating domestically to be repealed in the event of an "out" vote.
It also suggests the Government should establish a cross-party commission to reassert the supremacy of UK law and British courts.
Conservative former chancellor Lord Lawson, chairman of the judging panel, said: "The British people have been promised a referendum on whether the UK should leave the European Union. There are few more important decisions than this. In advance of that decision the issues need to be fully debated, and an essential element of the debate will be an understanding of how the UK might conduct itself if and when we leave.
"Iain Mansfield's prize-winning entry provides an excellent starting point for this important debate, written with the experience of a serving member of the diplomatic corps with a solid background in trade policy."
Mark Littlewood, director general of the Institute of Economic Affairs, said: "Given that Britain might decide to leave the European Union at some point in the next few years, it is important that the intellectual debate about how to construct a successful future for Britain begins now. Iain Mansfield is to be congratulated on providing such an excellent blueprint.
"The IEA's Brexit competition marks a crucial step in moving beyond a heated debate about the merits and demerits of our EU membership and instead to start to consider the options available to the United Kingdom if we opted to end our membership of the European Union."
