Summer 2016, and the Brexit referendum result cuts Britain down the middle - stunning Westminster and the world. It is the starting point of a series that will explore the consequences and reasons behind some of the most dramatic and chaotic political events seen in a generation. It will examine how close our political system came to breaking and if it will ever be normal again.

Spanning the premiership of three prime ministers, episode one begins with Theresa May assuming office and holding the responsibility for delivering on the referendum result. We hear from senior civil servants who have never spoken before about the absence of a plan for achieving Brexit, which kick-starts months of anguished rows within the Conservative Party over what a deal with the EU should look like.

For seven years, Laura was the BBC’s political editor and so held a ringside seat at these events. Talking now to ministers, advisers and officials who were in the room, we hear what was driving the divisions and why this period became so toxic and disordered in public and behind the scenes, with Laura adding her own considered reflections on the period.

Ministers from around Theresa May's cabinet table describe the lengthy debates that never reached any conclusion. Nick Timothy and Fiona Hill talk exclusively about their role as her secretive and powerful political advisors - sent to turbocharge Westminster on behalf of their political master. May's confidants were sent to conquer not cajole, but both stand accused by civil servants of 'terrorising' the system of government to get things done.

Unable to find a way through on Brexit, Theresa May took the gamble of her life. She called an election to strengthen her position but failed and lost her majority. Parliament refused to back any plan for Brexit, and British political life descended into chaos. The strength of feeling on both sides of the divide hardened, and Westminster began to feel like a war zone.

Theresa May was ultimately toppled, having failed to find the backing for her Brexit deal in parliament. It marks the perhaps inevitable arrival of Boris Johnson into Number 10 with his Vote Leave sidekick Dominic Cummings in tow. This chapter of politics ushers in a new, brutal approach towards conventions and rules. Parliament is brought to an early shutdown - prorogued - as senior civil servants wonder if the glue that holds our constitution together is tough enough for the plan Boris Johnson is pursuing. Even the Supreme Court’s ruling to suspend prorogation – as the prime minister’s advice to the Queen was unlawful - did not stop Johnson. We hear exclusively from the ministers, legal advisors and mandarins inside the room - looking on in astonishment. Show less