Morrison's work belongs to no particular school, but owes some debt to fairly unconventional (and largely Scottish) influences such as John Davidson and Harold Monro, as well as Welsh poets Alun Lewis and Dylan Thomas.

His work is often characterised by a strongly social and polemical tone, as epitomised in two of his long poems: Clocking-in for the Witching Hour (new revised edition, Smokestack 2010), which charts the thought processes of his father on a night shift as a security officer, through themes of ancestry and self-perceived failure; and the Blakeian Keir Hardie Street (new revised edition, Smokestack, 2010), in which a fictitious, turn-of-the-century, working-class poet discovers a Socialist Utopia off the dreamt-up Sea-Green Line of the London Underground..

Morrison’s work can also demonstrate an acute empathy for mental suffering, as in his openly confessional piece Feed a Cold, Starve a Fever (2004), in which he traces the possible origins of his own obsessive preoccupations to a childhood subtly punctuated by Catholicism.

Morrison’s most acclaimed work so far is Picaresque, a play for voices based on his experiences working at an all-male night shelter in Brighton, in which he juxtaposes the homeless "residents" with piratical alter-egos. The piece has been performed several times between 2000 and 2006, at venues including The Poetry Café and the George Bernard Shaw Theatre, RADA. Comparisons have been drawn with Dylan Thomas’ Under Milk Wood — ( DADA South and Samuel French Ltd.), but in terms of subject and tone other reviewers have seen the work as more echoing the likes of Robert Tressell and Maxim Gorky (Andy Croft, Smokestack).

His 2006 collection, The Mansion Gardens, was nominated for the 2006 T. S. Eliot Prize by publisher Paula Brown and critically praised in journals such as The London Magazine and Other Poetry. His 2009 volume, A Tapestry of Absent Sitters (Waterloo Press) demonstrates a further radicalising of his already distinctive voice with a wide breadth of style and subject and nods to his own poetical and political influences.

In August 2010 Morrison compiled, contributed to and edited an eBook collection of political poems entitled Emergency Verse - Poetry in Defence of the Welfare State endorsed by Caroline Lucas MP

Morrison worked for over a year as editor and designer of Poetry Express, journal of Survivors’ Poetry, (a mental health literary charity); a position in which he was able to promote the writing of other survivors of mental distress, most notably, David Kessel, whose collected poems, O the Windows of the Bookshop Must Be Broken, he edited, designed and prefaced. Since then, he has run a series of poetry workshops in his local community for mental health and disabled service users. In 2008 he gained an NHS Artists' Award to produce an anthology of writing through his workshops at Mill View psychiatric hospital, Hove (in 2009). He is also a Board Member (representing creative writing in mental health) for social arts enterprise Creative Future, in Brighton. Morrison is founding editor of radical literary webzine, the Recusant.

Morrison’s poetry has been published in over thirty journals including Aesthetica, Aireings, Illuminations (US), The London Magazine, Pennine Platform, The Penniless Press, Poetry Salzburg Review, Stand (2010) and The Yellow Crane; and online at Great Works, Strix Varia and Snakeskin.