Free trade, transparency and a crackdown on tax cheats will be at the heart of Britain's G8 presidency, Prime Minister David Cameron told the World Economic Forum in Davos on Thursday as he set out his vision for a more competitive Europe.

The speech comes a day after Cameron made headlines by promising the British people a vote on European Union membership if he wins the next general election in 2015.

"We need more free trade. We need fairer tax systems. We need more transparency on how governments -- and yes, companies -- operate," Cameron told political and business leaders at Davos.

These three issues will be the focus of the G8 meeting to be hosted by Britain later this year, he said.

Cameron said the European Union and the G8 -- made up of Canada, France, Germany, Italy, Japan, Russia, Britain and the United States -- all face the "looming, insistent question" of how to compete and succeed in the global economic race.

He sees free trade as key to that success, saying that when it isn't free, everyone suffers.

He wants Britain to be outward-looking, Cameron said, as he insisted that his referendum promise was "not about turning our backs on Europe" but about making the 27-member bloc work for everyone.

"Let's negotiate a new settlement for Europe that works for the UK and then let's get fresh consent for it. It's not just right for the UK. It's necessary for Europe," he said.

"Europe is being out-competed and out-invested -- and it's time we make it an engine for growth, not a source of cost for business and complaint for our citizens."

'Shape the future'

With this in mind, Cameron told CNN's Christiane Amanpour that he has no regrets over the referendum promise, despite unhappiness among some European partners.

"It's really important that we've set out a plan for how we get change in Europe that will benefit all of Europe, making it more open, more competitive, more flexible, and how we secure Britain's place within that," he said.

"I think it's a very important step forward and I'm pleased with the reception that the speech has got from the business community, from the public, and also some positive responses from some of my European colleagues in government, too."

As for those who have criticized the decision, Cameron said he believes "the greatest gamble for Britain would be to sit back and do nothing."

The European Union is already changing to meet the needs of the 17 members who are part of the euro single currency, he said. Britain is not in that group.

"It's much better in my view to step forward to shape that debate, to shape the future in Europe," he said.

Britain's desire to renegotiate the terms of its EU membership is based on the need to gain the consent of the people as they follow a path within Europe, he said.

Far from being isolationist, Britain is a "very positive player" in the European Union, Cameron added.

In addition to helping create the single market, it has been one of the nations that pushed for the oil embargo on Iran and tough sanctions on Syria, and it has become a key backer in recent days of France's military action in Mali, he said.

Asked about the recent wrangling in the United States over the fiscal cliff, Cameron suggested that America could learn from Britain, although he recognizes that every country's circumstances are different.

"I would say our experience in the United Kingdom is that you can take people with you as you take those difficult decisions, but ... it's a very tough and hard road, but it's a road we all have to travel," he said.

"In the end, we all have to prove that we can pay our way in the world, that our credit is good, and all the rest of it. It's not the only way that you will get growth; it is part of what we need to bring the world economy back to healthy growth."

Cameron said the biggest thing that Britain and America could do together is to work on an EU-U.S. trade deal.

"Between us, we account for a third of world trade, so if we really got together and liberalized trade between the European Union and the United States of America, we could make both our peoples a lot better off," he said.

'Ethical issues'