Benedict Cumberbatch as Dominic Cummings

Rory Kinnear as Craig Oliver

John Heffernan as Matthew Elliott

Oliver Maltman as Michael Gove

Richard Goulding as Boris Johnson

Simon Paisley Day as Douglas Carswell

Lee Boardman as Arron Banks

Lucy Russell as Elizabeth Denham

Paul Ryan as Nigel Farage

Kyle Soller as Zack Massingham

Liz White as Mary Wakefield

Tim Steed as Daniel Hannan

Kate O'Flynn as Victoria Woodcock

Nicholas Day as John Mills

Tim McMullan as Bernard Jenkin

Richard Durden as Bill Cash

Gavin Spokes as Andrew Cooper

Ronak Patani as Leave Intern Ameet

Mary Antony as Leave Intern Katie

Neal Barry as Geoff

Sophie Stanton as Lyndsey

Henrietta Clemett as Lucy Thomas

Aden Gillett as Robert Mercer

Annabelle Dowler as Focus Group Facilitator

Gabriel Akuwudike as Robin

John Arthur as Roger

Rakie Ayola as Camilla

Jay Simpson as Steve

Heather Coombs as Sandra

Kiran Sonia Sawar as Shamara

Andrew Barclay as Breitbart TV Interviewer

Ian Morine as Boris Johnson Staff Member

Ross Hatt as Policy Strategist

Theresa May as Self (archive footage)

Vladimir Putin as Self (archive footage)

Boris Johnson as Self (archive footage)

Jeremy Corbyn as Self (archive footage)

David Cameron as Self (archive footage)

Winston Churchill as Self (archive footage)

Margaret Thatcher as Self (archive footage)

Mark Gatiss as Peter Mandelson (voice)

Mark Dexter as David Cameron (voice)