Alex Salmond told MSPs the SNP had increased free nursery provision from 425 hours in 2007 to 475 hours, and that new legislation would take that figure to over 600 hours.
Mr Salmond had been accused of "letting down" families and children by failing to bring in a pledge on free childcare sooner, during first minister's questions on 15 March 2012.
Labour leader Johann Lamont said working parents needed action now to help them cope with costs.
She said: "What families need is action now, not a clause in a Children's Bill, and not a two-year delay."
The Scottish Labour leader went on: "Families don't need legislation in the future, they need a Government now which will provide the funding to deliver reliable and affordable childcare when people need it".
The Scottish Government plans to introduce a Children's Bill to Holyrood next year, which will include a statutory guarantee of over 600 hours of free nursery education for every Scottish three and four-year-old and for every looked after two-year-old.
Mr Salmond today urged his Labour rival to commit to supporting the legislation, saying it would enshrine the pledge in law and "will make available 600 hours to the families across Scotland".
The first minister said: "If the Labour Party was so keen on this issue, why on earth didn't they implement it in the eight years they were in power?".
Scottish Conservative leader Ruth Davidson called on Mr Salmond to introduce a Scottish Cancer Drugs Fund to pay for drugs like Abiraterone.
The Scottish Medicines Consortium (SMC) decided the cost of abiraterone at £3000 a month did not justify the health benefits seen.
Mr Salmond the drug company could reapply to the SMC and there was also the option of individual patient treatment requests.
He said that 60% of drugs submitted to the SMC on a reasonable cost basis were then approved.
Scottish Liberal Democrat leader Willie Rennie asked the first minister to guarantee that he would not "give in to Brian Souter" and would support equal marriages for gay couples.
Mr Salmond said the government was in the process of a consultation which had received a massive number of responses and it was right and proper to allow the consultation process to take its course.