We follow two relatively new female MPs – Charlotte Leslie and Sarah Champion – learning the ways of the House. We hear from those at the top of political tree including David Cameron and Ed Miliband, who reveal what happens at prime minister's questions, and we also see behind the scenes on budget day. We meet a maintenance team abseiling down the face of Big Ben and the gospel-singing tea lady Gladys who works in the members' tea room. We also follow the Commons' most powerful official, the clerk of the house Sir Robert Rogers, whose job is to keep the whole show on the road.

Cockerell explores the upstairs-downstairs world of the House of Commons. We see what goes on backstage at the state opening, when the Queen comes to open the parliamentary year, including a surreal traditional search for gunpowder. Behind the pomp and pageantry, we meet the army of skilled workers who struggle to keep the Commons show on the road. We follow MPs who want to introduce their own bills in the Commons and have to play a bizarre form of parliamentary bingo to get the chance. And we show how Labour and Conservative MPs conspire together to thwart their party whips. Meet two very different MPs: Robert Halfon, a campaigning Conservative and thorn in the side of the government, who receives an unexpected call from Downing Street. And Thomas Docherty, Labour's deputy-shadow leader of the house, who goes to extraordinary lengths and makes unlikely alliances to guarantee time in the chamber for his party.

In the third episode of this major four-part series, presenter Michael Cockerell sees how the traditional three-party system appears to be falling apart at the seams. Back-bench MPs are becoming increasingly rebellious as they confront the dark arts of the whips - the shadowy figures who seek to impose party discipline. Michael follows Lib Dem MP Jenny Willott as she seeks to balance new parenthood with politics. And we follow the clockmakers whose job it is to ensure that all the Commons' 2000 clocks, from Big Ben downwards, tell exactly the same time.

In the final part of this major four-part series, battles break out over the future of the House. Speaker John Bercow runs into trouble with his own plans for reforming it. Wealthy Tory backbencher Zac Goldsmith tries to give voters the power to sack their MPs - and the establishment tries to stop him. Plus the ongoing struggle to conserve the Victorian mock gothic palace and anticipate the challenges of carrying out a multi-billion pound programme of restoration work whilst the House is sitting. David Purdue of the events and banqueting team is part of a new initiative to raise money for the upkeep of the House by hosting fashion shows and film premieres inside the House. At the end of a remarkable year, conflict continues between those who celebrate the Commons' historic traditions and those who believe it needs to be dragged kicking and screaming into the 21st century, as MPs gear up for the general election. Many face the prospect of losing their jobs. The ever-changing House of Commons will soon have a new intake of MPs, and new challenges to face.