The result of the UK's EU referendum vote came as a shock to many across the world. It's now causing uncertainty and concerns in the EU, and some politicians in other member states have proposed following UK's example.

There is no concealing the sense of alarm spreading through the European Union.

"I am fully aware of how serious, or even dramatic, this moment is politically. And there's no way of predicting all the political consequences of this event," said Donals Tusk, President of European Council.

And the question now is what happens next. Is the Brexit going to be a quickie divorce or could this be long and painful?

"European leaders will want to make things difficult for the UK as they do not want this to become a precedent for other countries and think: well, at the end, it is very easy to leave the EU, and not have any economical damage for this and keep the advantages of the free market," said Dave Sinardet, political analyst.

Other Eurosceptics are already jumping on the Brexit bandwagon. France's far right leader Marine Le Pen on Friday called for a French exit - a Frexit, if you will.

"This referendum on France being part of the European Union is a democratic necessity. The French also need to be able to choose this path of freedom which will give France back its full sovereignty," said Marine Le Pen, French Far Right Party leader.

The fear in Brussels is that populist parties across the continent could see the British vote as an opportunity to abandon the "European Project".

When the Commission President was asked if this is the beginning of the end of the EU his answers was no. 

It was hardly convincing. These are uncertain times. The EU is in unchartered waters now. And behind closed door leaders, as leaders craft a detailed response to the Brexit. They'll also be wondering how to stop other members following in the UK's footsteps.