The UK's divorce procedure with the EU will only start when the country formally notifies its intention to leave, activating Article 50 of the Lisbon Treaty.

While a new government needs time to prepare itself, many EU leaders are calling on the UK not to waste time in starting the procedure.

A flurry of diplomatic activity across Europe on Monday in the wake of the so-called Brexit. The leaders of ALL 28 EU countries - including the UK - will meet in Brussels on Tuesday.

Europe's big guns want the UK to get on and start the Brexit talks. But there's not much they can do about it.

This is the Lisbon Treaty a 400 odd page agreement which forms the constitutional basis of the European Union. And this is Article 50 - just five short paragraphs that everyone is talking about at the moment because it is this clause which gives the UK the right to leave the union. 

But it's worded in such a way that the EU has no legal means to force the UK to launch the exit procedure. And that means the Brexit headache could drag on.

"The main problem of Article 50 is that there is no time limit, there is no deadline set up in this provision. And of course, the burden is on the UK government to open or not this process," said Stephane Rodrigues, lawyer.

Leading Brexit campaigners including Boris Johnson are demanding informal withdrawal talks before locking Britain into the strict two-year time frame laid down in the Article 50 process. 

But the leaders of Germany, France and Italy have ruled that out

"So not wasting any time, as Angela Merkel says, it means making sure that the notification by the British is done as quickly as possible, it means there can be no discussions in advance of this notification," said Francois Hollande. 

"And once it has been announced, when it is transmitted to the European institutions, then the phase of negotiations can begin under Article 50. It is better for the whole of Europe that we have that procedure and that it starts as soon as possible."

It's a move designed to put pressure on the UK and to try and stop other countries following Britain out of the door amid market fears that the bloc is "no longer governable".