[1] Between 1967 and 1969 he directed various ITV productions including plays by Alun Owen (Shelter, George's Room, Stella, Thief, Gareth), Edna O'Brien (Which of These Two Ladies Is He Married To?

[4] A number of his works achieved notoriety and widespread criticism from the conservative end of the political spectrum,[citation needed] including Scum (1977), dealing with the subject of borstals (youth prisons), which was banned by the BBC, and subsequently remade by Clarke as a feature film released in 1979 (the original television version was only screened after his death).

[citation needed] Clarke's work in the 1980s was fiercely stark and political, including the David Leland plays Beloved Enemy (1981) on multinational corporations and Psy-Warriors (1981) on military interrogation.

[3] His film work became more sparse, culminating in Contact (1985) on the British military presence in Northern Ireland, Billy the Kid and the Green Baize Vampire (1985), Road (1987), and Elephant (1989).

Elephant, lasting only 37 minutes, dealt with 'the troubles' in Northern Ireland by featuring a series of shootings with no narrative and minimal dialogue; all were based on accounts of actual sectarian killings that had taken place in Belfast.

[7] The film took its title from Bernard MacLaverty's description of the troubles as "the elephant in our living room" – a reference to the collective denial of the underlying social problems of Northern Ireland.

His final production of Al Hunter's The Firm (1989), covered football hooliganism through the lead character played by Gary Oldman, but also explored the politics of Thatcher's Britain.

Another project, a script by David Yallop entitled In God's Name, also went unmade as Clarke began radiotherapy for cancer which by that time had spread from his lungs to his spine.

Clarke inspired a generation of actors, writers and directors, including Paul Greengrass, Stephen Frears, Tim Roth, Ray Winstone, Gary Oldman, Danny Brocklehurst and Iain MacDonald.