They say it would start July 2015 if their crucial May 1 budget passes in the legislature.
The annual maximum payment per child under the age of 18 — which is available to families making $20,000 or less a year — will rise to $1,310 this July.
Over half a million families receive the credit to support about one million children, according to government officials. The province is expecting to spend about $1.08 billion on the child benefit in the current fiscal year.
The minority Liberals are also proposing to spend $269 million to raise wages for early childhood educators and other child care workers.
They say it would increase pay by an average of two dollars an hour, with the first increase starting in January 2015.
The Liberals need at least one opposition party to support their budget to avoid an election.