May will remain as Prime Minister for a few more weeks, but the race is already underway to find a replacement. The key issue will be how to tackle Brexit. CGTN's Jamie Owen spoke to a former close adviser to Boris Johnson, one of the front-runners for prime minister.

JAMIE OWEN CGTN "Prime Minister Theresa May leaves, we get a new prime minister, does it actually change anything?"

GUTO HARRI POLITICAL ANALYST & FORMER ADVISOR TO BORIS JOHNSON "Well, the parliamentary arithmetic, how the votes stuck up in our parliament doesn't change. The reality that the European Union say there's no better deal on the table probably doesn't change. And the reality that the British people have voted for us to leave the EU doesn't change. So it could be the worst job ever to take over in a situation where you can't change a thing."

JAMIE OWEN CGTN "The front runner to be the new leader of the conservative party is the former London mayor Boris Johnson, you worked for him, what's he like?"

GUTO HARRI POLITICAL ANALYST & FORMER ADVISOR TO BORIS JOHNSON "I know him well, I met him at university, I worked closely for him for four years. He is hugely intelligent, enormously charismatic, quite off the beat, he breaks the rules, he does the kind of things that people don't expect politicians to do. He speaks what's on his mind. And he has a combination of charm, and originality that can unlock situations. But he has to decide in the end, is he prepared to take Britain out of the EU without any deal that sets formal parameters for that. And probably define the British parliament, which would be a bold, some would say foolish thing to do."

JAMIE OWEN CGTN "We have days to go until we find out who the next conservative leader will be. If you had to call it today, who's it gonna be?"

GUTO HARRI POLITICAL ANALYST & FORMER ADVISOR TO BORIS JOHNSON "The wind is in Boris Johnson's sail. The momentum is with him, when Donald Trump endorsed him this week. That doesn't swing votes here, but it creates a sense of inevitability that Boris is going to be prime minister. And I think most people are now pointing out whether they want this come out or not, of assuming that's where we are heading. It ain't over, there are other people in cabinet, there's the foreign secretary, there's Michael, who's up against Boris before, and ended his campaign. There are people who may yet take the wind out of his sails. But at the moment he looks like he will fulfill his childhood dream of being prime minister of Great Britain."