Under the decree, which sparked heated public debate when it took effect six months ago, children cannot enrol in a creche or kindergarten unless they have been vaccinated against measles as well as nine other diseases.
Parents of unvaccinated children aged between six and 16 face fines of up to €500.
Previously only four vaccines – not including measles – were mandatory.
Now the far-right Northern League and the populist Five Star Movement (M5S) are proposing to scrap the decree ahead of the March 4th elections in which the two parties and a divided left will go up against a strong centre-right coalition.
M5S leader Luigi Di Maio says the law should revert to the previous four compulsory vaccines, while adding measles, after last year's outbreak sickened nearly 5,000 people and killed four.
He notes that Italy's measles immunisation rate of 87 percent is far below the 95 percent threshold recommended by the World Health Organization.
Northern League leader Matteo Salvini opposed the decree from the start, saying that while he had his children vaccinated he believed the shots should be optional.
The stance is at odds with the party's ally, the conservative Forza Italia movement of former prime minister Silvio Berlusconi, which voted in favour of the measure last year.
Meanwhile, ruling Democratic Party leader and former premier Matteo Renzi said he backs the law.
"You don't mess around with vaccines. The health of our children is at stake, not an extra [percentage] point at the polls. We are on the side of science, research and medicine and won't turn back."