In 2011 Nigel was cast in the lead of Shrek The Musical as we all know Shrek has a Scottish accent, to help him prepare he asked his friend David to help:
“It is a hell of a part. [The producer] Caro Newling said to me, 'It’s like the King Lear of musicals.’ They told me that, for this, they saw a lot of actors who can sing, rather than musical actors, because the make-up and padding are so thick, you need to see a bit of humanity come through.” Vocally, they may also hear a touch of Time Lord. “I phoned David Tennant, who is a mate, and said, 'I want to do a hybrid of you and Kenny Dalglish. He said, 'If you do Kenny no one will understand it.’ I said, 'Yeah but you’re too fey.’ He said, 'I’ll butch up for you.’ I went round to his place and he read a bit of the script for me.” - The Telegraph - May 4, 2011 - Jasper Rees
Here's Nigel as Shrek -