The campaign for May's Scottish Parliament election has not been ambitious enough, the leader of the STUC will say. Grahame Smith, general secretary of the Scottish Trades Union Congress (STUC), will say the campaign so far "doesn't yet reflect the possibilities provided by new powers". Smith, who will make the remarks at the launch of the STUC annual congress, believes May's vote will be "the most important election to take place since the Scottish Parliament was re-established in 1999". He will say: "The next Scottish Government will wield new powers on tax, welfare and employment programmes, powers with the potential to make a substantial, positive difference to the lives of working people in Scotland. The next Scottish Government really has to aspire to more than just managerial competence. "Unfortunately, the campaign going on around us doesn't yet reflect the possibilities provided by new powers. Indeed, the nature and quality of debate suggests that it could take some time for our political parties to recognise that new opportunities exist, let alone grasp them." Smith wants to see "bold, ambitious policies" that will attempt to solve long-standing issues in Scottish society like poverty and inequality, "based on the evidence of what works rather than their populist appeal or soundbite suitability". He will also warn low voter turnout, followed by an "uninspiring programme for government", could lead to division across the country. In a statement ahead of the Holyrood vote, the STUC is calling on the next Scottish Government to enact "significant tax reform" to target high earners, scrap the council tax in favour of a "steeply progressive property tax based on regular revaluations", and oppose the UK Government's controversial Trade Union Bill. The STUC annual congress begins in Dundee on Monday and will see keynote speeches given by the First Minister Nicola Sturgeon and Scottish Labour leader Kezia Dugdale. Responding to Smith's remarks, the Scottish Greens issued a lengthy statement outlining their proposals to introduce a 60p top rate of tax for the "super-rich", replace the council tax and invest in sustainable jobs. Co-convener Patrick Harvie said: "Of the five main parties in the Holyrood election, we are the only party whose tax proposals include the introduction of an additional tax band, and the only party that will seek to increase income tax for the super-rich beyond 50%." He added: "Greens support non-compliance with the Tory government's Trade Union Bill, deeming it an attack on workers' rights." A spokesperson for Scottish Labour claimed their party had "led the debate on using the new powers to provide an alternative to austerity". The spokesperson added: "Analysis by the IPPR this week found that the difference between Labour's plan to use the powers and tax the rich, and the SNP plan to do nothing, was an extra billion pounds fewer cuts a year." The SNP's business convener Derek Mackay said: "With new powers coming to the Scottish Parliament, this election is the most important since devolution - and it is clear that the SNP is the only party with the ideas and ambition to use them to build a fairer, more prosperous country. "A re-elected SNP Scottish Government will use the new powers to put dignity and respect at the heart of our social security system, give children the very best start in life and to invest more in our public services. "The First Minister will address the STUC this week and will set out our vision for further improving Scotland." The leader of the Scottish Liberal Democrats Willie Rennie said his party's proposal to raise the basic rate of tax by a penny to fund education was "just one of the ambitious ways we plan to use the new powers coming to Holyrood". Rennie also said: "We were the first party to suggest changing income tax levels and we are the only party that has set out clearly what we would spend the half a billion pounds on that our plan would raise. This is our chance for a transformational investment in our nurseries, schools and colleges. "In comparison, the SNP and the Tories would rather stick to the UK Government's hymn book. That's not ambitious, it's just timid." The Scottish Conservatives have been approached for comment. 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.