Rhys Ifans is to star in a new monologue at the NT Shed later this year centring on the Occupy London movement.
Ifans, whose film credits include Notting Hill and The Boat that Rocked, will play Danny, who sleeps rough on the steps of St Paul's Cathedral and one morning wakes to see a canvas city being erected in front of him.
Tim Price's plays include I'm With the Band and Demos for the Traverse Theatre, The Radicalisation of Bradley Manning (National Theatre Wales), and Salt Root and Roe.
Protest Song runs in the NT Shed, a temporary venue constructed in the National Theatre square, from 19 December to 11 January (previews from 16 December).
Godley stars in Morning to Midnight
The production, which opens in the NT Lyttelton on 26 November 2013 (previews from 19 November), will be directed by Melly Still, whose previous credits at the National include Coram Boy and The Revenger's Tragedy.
Adam Godley's previous appearances at the National include the title role of Howard Brenton's Paul, Martin McDonagh's The Pillowman and Terry Johnson's Cleo, Camping, Emmanuelle and Dick. His other stage credits include Rain Man opposite Josh Hartnett in the West End.
Kaiser's 1912 play explores the tragedy of an ordinary bank clerk who steps outside his humdrum life and, over the course of one crazy, alienating day, destroys himself.
Other newly announced productions at the National include a new play by Nick Payne (Constellations, The Same Deep Water As Me) directed by Carrie Cracknell, which will run in the NT Shed from mid-January 2014.
The play is billed as a "blistering journey through the minefield of contemporary gender politics. With songs."
Carrie Cracknell's recent work includes A Doll's House (Young Vic and West End) and Wozzeck (ENO).
Stars mark 50 years
Also announced today are further details of the National's 50th birthday celebrations which, as previously reported, includes a star-studded gala night on 2 November.
According to press material: "From Rosencrantz and Guildenstern Are Dead to The History Boys, from Antony and Cleopatra to Angels in America, from Guys and Dolls to London Road, this will be a thrilling evening of live performance and rare glimpses from the archive, featuring many of the most celebrated actors who have performed on our stages over the past five decades."
Helmed by artistic director Nicholas Hytner, the cast includes Simon Russell Beale, Frances de la Tour, Judi Dench, Ralph Fiennes, Michael Gambon, Derek Jacobi, Alex Jennings, Rory Kinnear, Adrian Lester, Anna Maxwell Martin, Andrew Scott, Maggie Smith and Penelope Wilton, with more to be announced.
Other events marking the 50th anniversary include a new two-part BBC Arena documentary charting the venue from Laurence Olivier to the present day, and a series of 'encore' NT Live screenings including Hamlet (22 October), Frankenstein (31 October) and The Habit of Art (7 November).
There will also be a series of platform discussions, exhibitions and tours reflecting on the National Theatre's half-century.