Ed Balls has insisted that Labour has "no plans" to withdraw child benefit from parents who refuse to have their children vaccinated against measles, mumps and rubella with the MMR jab.
Press reports suggested that the punitive plan was being considered by Labour MP Jon Cruddas, who is in charge of drawing up the party's manifesto for the 2015 general election.
But Mr Balls said he was not aware of any discussions taking place, and insisted Labour would never make benefits conditional on a child's record of immunisations.
The shadow chancellor told ITV1's Daybreak: "There is no question of a Labour government ever taking child benefit away or punishing parents for choices they make on vaccinations.
"I don't know where that came from. It is not our policy. It is on the front of the newspapers but it is not true.
"There are no plans that I know of, or anyone knows of, to consider that. We would never say child benefit is conditional on taking a jab."
Unlike Labour's former prime minister Tony Blair, who famously refused to say whether he had given his children the MMR jab, Mr Balls had no qualms about confirming that he and wife Yvette Cooper - the shadow home secretary - have immunised their three children.
"We gave our children the MMR jab because it is the best way to keep your children safe," said the shadow chancellor. "That is what the best medical advice is, but parents should choose that."