The Sri Lankan's famous -- or infamous -- doosra delivery is expected to become legal once ICC chiefs have ratified a proposal from a committee to allow bowlers to flex their arms at the elbow by up to 15 degrees during a delivery.
The move follows research that indicated most bowlers in history have released the ball with a bent arm -- although this was only rarely visible to the naked eye.
But former England batsman Boycott claimed the development was nothing to do with consistency and fairness, describing it as a "sad day for cricket."
The blunt-speaking Yorkshireman told the BBC on Wednesday: "I think it's been brought in through pressure from Sri Lanka and Murali's supporters. It's a sad day for cricket that this pressure can allow Muralitharan to bowl whatever he wants."