In 2008 he appeared in Lark Rise to Candleford, a BBC production based on three semi-autobiographical novels about the English countryside written by Flora Thompson.
Daniels has also played a number of real-life characters, such as German State Secretary Dr.
Josef Bühler in Conspiracy, a 2001 dramatisation of the Wannsee Conference at which the Final Solution was endorsed.
He also played the author and journalist Ian Fleming, creator of James Bond, in Ian Fleming: Bondmaker (2005), as well as Sir Francis Walsingham in The Virgin Queen (2005) and English writer Saki in Who Killed Mrs De Ropp? In addition, he has made guest appearances in a number of British TV drama series, including Soldier Soldier (1992), A Touch of Frost (1992), Outside Edge (1994), Spooks (2005), and Merlin (2011).
He was offered roles in the 2000 releases The Patriot and Vertical Limit, but turned them down and stated that "the money was good, but it wasn't for me".
He appeared in All's Well That Ends Well and As You Like It (1999–2000), and played Mercutio in a 1994 TV adaptation of Romeo and Juliet.
One of Daniels' earliest roles was as Justin Hayward, the lead singer of the Moody Blues, as a teenager in two of the band's music videos, "Your Wildest Dreams" (1986) and "I Know You're Out There Somewhere" (1988).
In 1992, he made an appearance in the infamous plane crash episode "Cascade" of the television show Casualty, playing the co-pilot of the doomed plane.
The film was nominated for a Golden Seashell award.
Other feature films that Daniels has starred in are The Bridge (1992), I Want You (1998), Madeline (1998), and Doom (2005).
Daniels said in an interview: "Homophobia is still shockingly prevalent in film and TV.
I know I've lost work because of being gay, and it is always an issue.
A fellow student recalled that Daniels, whom he knew as Dave, "was very serious about his work, and struck me as incredibly intelligent...