While Prime Minister David Cameron's speech this week -- voicing his intent to let the British people vote on whether to stay in the European Union -- has caused concern on the continent, the mayor of London says it's all part of democracy.

"I think if you ask most international business leaders, bankers whether they wanted to abolish elections to remove any element of uncertainty in the commercial world, well of course they would love to do that," Mayor Boris Johnson told CNN's Richard Quest.

"You've got to consult the people form time to time, the British people haven't been consulted since 1975, the French have, the Dutch have, the Irish have -- now is the moment."

Cameron made headlines Wednesday by promising the British people a vote on European Union membership if he wins the next general election in 2015.

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.

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

After Cameron's speech on Wednesday, the President of the European Parliament Martin Schulz tweeted: "#Cameron's Europe a la carte not an option. We have to focus on jobs & growth rather than getting lost in treaties discussions." French Foreign Minister Laurent Fabius used similar language in an interview on France Info radio saying Europe could not be "a la carte," Agence France-Presse (AFP) reported.

Johnson believes any vote would result in Britain remaining in the EU. "I think most people can see that the overwhelming likelihood, in fact the certainty, is that Britain one way or another will be part of the free trade zone," he said.

Johnson also condemned attempts in Europe to build financial trading hubs away from London. Last month, the governor of the Banque de France told the Financial Times the City of London should be deposed as the euro's main financial center so the single currency club can "control" most financial business in the eurozone.