Neil Lennon’s men only need a draw against Kilmarnock at Rugby Park today to wrap up a championship that looked out of their reach in November when they fell 15 points behind Rangers.
Celtic had leapfrogged their Old Firm rivals by the time the ailing Ibrox club were deducted 10 points in February for entering administration.
The punishment effectively ended Rangers’ title challenge and subsequently, in some quarters, doubt has been cast on the validity of Celtic’s almost inevitable championship win.
However, the former Celtic midfielder said: “This would, I think, be sweeter than anything I achieved.
“All this talk of tainted titles from pundits writing this and writing, is an absolute nonsense.
Meanwhile Ally McCoist is cautiously optimistic that Rangers are finally heading in the right direction as administrators edge closer to identifying a preferred bidder for the club.
Duff and Phelps believe the Scottish champions could be out of administration by the end of the season, after confirming they will give further consideration to three of the four bids submitted for the club earlier this week.
McCoist said: “I speak to the administrators on a regular basis and there have been three very positive bids for the club.
“The administrators have been quoted as saying they are pleased and now see a bit of light at the end of the tunnel which is positive.”