During the most volatile period in Westminster's recent history, Giles Dilnot discovers the role of the whips, the mysterious and shadowy figures of parliament.

As a rule of thumb, parliamentary whips are silent. They cannot afford to hold a view in public, they don't do media. Instead they hold a mysterious, shadowy status. But in this programme, it's a status which political reporter, Giles Dilnot, will uncover.

The myth of the whip is one thing - the disciplinarians who do their party's dirty work - ensuring their party members stick in line, do as they're told, and turn out and vote when needed. They'll resort to any means necessary to get what their party needs. As one former whip tells us, he was appointed "flusher" as assistant whip. It was his role to prowl the depths of parliament armed with a screwdriver, to unscrew the doors to the toilets flush out any of his MPs avoiding a vote: "I thought it a strange road to socialism".

Dissenters have long criticised the whips as a barrier to real democracy and freedom of speech for this reason - but what would happen without them?

As Giles discovers,their role extends far further than just disciplinarian. They are the lubricant in the system, the wheels on the vehicle, the stage managers to parliament's stage.

As the programme was recorded, the parties face an unprecedented political landscape - through the referendum and its aftermath both Labour and Tory parties are left divided. Giles speaks to whips, past and present, during this most testing time. What is their role in this time of flux and who do they work for?

From Callaghan's vote of no confidence in 1979, to Maastricht, to coalition of 2010 - how do they handle a crisis? As the parties' fire fighters, has their role changed? And how will they handle the huge flames of summer 2016?

Featuring Rosie Winterton, Anne Milton, Andrew Mitchell, Jacqui Smith, Lord Snape, Lord Heseltine, Lord Howard, Jack Straw, Caroline Lucas, and Professor Philip Cowley.

Producer: Polly Weston.