With less than three weeks to go until the Scottish Parliament election, party leaders have been out chasing votes across Scotland. Education, business and a future independence referendum were all on the agenda over the weekend, as May 5 moves ever closer. Ahead of her party's manifesto launch on Wednesday, Nicola Sturgeon promised the SNP would never support the "twin relics" of Trident and the House of Lords. In comments made on Saturday, the SNP leader said: "Rather than slashing public spending with their austerity obsession, David Cameron's Tories should look closer to home to find savings." On Sunday the party announced plans for a new Climate Change Bill if re-elected that would see Scotland's current carbon emissions target raised from 42% to over 50%. Climate Change Minister Aileen McLeod admitted meeting emissions targets "has not always been easy". Nicola Sturgeon also said the decision to hold another independence referendum would need the support of a majority of Scots, but that "a significant and material change in the circumstances that prevailed in 2014" - such as Scotland being taken out of the EU against its will - could act as a trigger. Campaigning in Rutherglen on Saturday, Scottish Labour leader Kezia Dugdale pledged to "tax the rich" and "stop the cuts", and promised investment in education. Dugdale travelled to Edinburgh on Sunday to promote her party's plan to invest £40m in after-school sports. She said Labour would pay for it by using Barnett consequentials from the new sugar tax, estimated to deliver in revenue an average of over £100,000 per secondary school, dependent on school rolls. The Labour leader said the policy could bring about "a revolution for after-school sport in Scotland", adding: "The positive benefits of sport and healthier lifestyles for our young people will be felt all across our country, from less pressure on our NHS to higher achievement in our classrooms." Tory leader Ruth Davidson spent her Saturday in the south of Scotland to highlight her party's proposals to boost business in the area. She promoted her party's manifesto pledge to set up a South of Scotland Enterprise, similar to Highlands and Islands Enterprise (HIE), to grow the economy. She said: "A dedicated agency in the Highlands and Islands has done very well to develop the jobs and opportunities of the future, we think the south of Scotland should get a dedicated agency too." Davidson was also interviewed on the BBC's Sunday Politics, where she said that if she became leader of the opposition at Holyrood she would "say no to a second referendum". Party leader Willie Rennie was in Bridge of Allan on Saturday, where he challenged the other parties to match his vision to make Scottish education "the best again". He cited Lib Dem pledges to raise a penny on income tax, invest in childcare and early years learning and reverse college cuts. On Sunday the party's energy spokesman Liam McArthur called the SNP's climate change pledge "laughable", adding : "Scotland has missed its climate change targets for four years in a row." Rennie also criticised Tory leader Ruth Davidson for matching George Osborne's "tax cuts for the richest" and for being "silent over disability benefit cuts". He claimed she was "in the Chancellor's pocket". Co-convener Patrick Harvie and culture spokesperson Zara Kitson were in Glasgow on Saturday to celebrate Record Store Day. Kitson said: "The Scottish Greens support independent, local business, and recognise the value the music industry brings to city life and culture in Glasgow and beyond." On Sunday, the party's climate change spokesperson Mark Ruskell also criticised the SNP's climate change announcement, saying: "Setting targets is one thing; implementing the policies to make the difference is quite another." Patrick Harvie added: "To set new targets while cutting the energy efficiency budget and proposing a tax break for aviation shows that there's still too much focus on media announcements and not enough on action." Download: The STV News app is Scotland's favourite and is available for iPhone from the App store and for Android from Google Play. Download it today and continue to enjoy STV News wherever you are.