He also appeared in the television series The Kit Curran Radio Show (1984–1986), Holby City (2002–2004, 2019), and New Tricks (2012–2015), and reprised the role of Antilles in the film Star Wars: The Rise of Skywalker (2019).

He then sold carpets and did amateur theatre work for a year in Dundee before auditioning again at RADA in London and successfully at RSAMD in Glasgow.

and has since starred in television dramas such as The Merchant of Venice (1973) opposite Laurence Olivier as Shylock, Rock Follies (1976) and Dead Head (1986).

In 2005, he played the leading role of John Jarndyce in the critically acclaimed BBC adaptation of Charles Dickens' Bleak House, receiving an Emmy nomination.

He also appeared in the West End playing the character of Georges in the revival of the musical hit La Cage Aux Folles.

He starred as the lead in Above Their Station, a sitcom for the BBC written by Rhys Thomas about Community Support Officers; it was made as a pilot but never commissioned, being shown only as a one-off special.

In July 2009 Lawson appeared as Alexander Fleming in a BBC Four drama called Breaking the Mould: The Story of Penicillin alongside Dominic West.