Coltrane will appear in an episode about Scottish independence, it was confirmed at a UKTV launch this morning.
UKTV's chief exec Darren Childs said: "The stories are topical and up-to-date. There are episodes about coalition, the euro crisis and Scottish devolution.
"And Robbie Coltrane has agreed to play a very key part in that [Scottish] episode, which is exciting."
Gold is bringing back the classic political comedy for six 40-minute episodes in early 2013. Original writers Jonathan Lynn and Sir Antony Jay have penned the scripts.
David Haig, Henry Goodman and Chris Larkin, who appeared in the stage show version of the comedy, will star as Jim Hacker, Sir Humphrey Appleby and Principal Private Secretary Bernard Woolley in the TV update.
Gold is also making an hour-long documentary about the original series and its prequel Yes, Minister, which ran from 1980 to 1988, and was reportedly Margaret Thatcher's favourite TV show during the '80s.
Watch a clip from the classic Yes, Prime Minister series below: