The Scottish National party has committed to a £2.5bn boost to frontline NHS spending, a freeze on income tax throughout the next parliament and the abolition of NHS dentistry charges, in what Nicola Sturgeon described as an “unashamedly optimistic” manifesto while warning that the outcome of next month’s Holyrood election was “on a knife-edge”. The manifesto also states that the party intends to hold a second independence referendum “within the first half of the five-year [parliamentary] term” – before the end of 2023 – provided the Covid crisis is over by then. Sturgeon said it would be “a dereliction of my duty as first minister” to hold a referendum while the pandemic was ongoing, but added: “It would also be a dereliction … to let Westminster take Scotland so far in the wrong direction that we no longer have the option to change course.” Reiterating her certainty that Westminster could not stand in the way of a pro-independence majority at Holyrood, she said: “After this election, if there is a simple, democratic majority in the Scottish parliament for an independence referendum, there will be no democratic, electoral or moral justification whatsoever for Boris Johnson or anyone else to block the right of people in Scotland to decide their own future.” There were also pledges on pilot schemes that would examine the feasibility of providing a minimum income guarantee and a four-day working week, but enacting these would be dependent on Holyrood gaining further powers over benefits and employment rights. Other commitments include: In addition to a 20% increase in frontline NHS spending, a £10bn programme of investment in NHS facilities, and a minimum 25% rise in mental health spending. Establishing a national care service, backed by a 25% increase in social care investment. Doubling the value of the Scottish child payment to £20 a week for every child in a low-income family. A national digital academy allowing people to gain high school qualifications regardless of age or location. Bonds of up to £50,000 offered to young people and families to stay in or move to islands to tackle rural population decline. Asked how she intended to fund the plans, given the freeze on income tax, Sturgeon said all the spending commitments in the document, which by the last year of the parliament would amount to an additional £6bn, fell within the middle scenario of financial forecasts by the independent Scottish Fiscal Commission assessing growth in tax revenues and block grants. Referencing a report by the Institute for Fiscal Studies published on Wednesday, which described Scotland’s devolved tax and benefit powers as the most progressive in the UK, Sturgeon said that even with the tax freeze, “people with the broadest shoulders already pay more” and that “progressive principle is front and centre”. But in its own analysis of the manifesto, the Institute said that free dentistry was likely to benefit the better off, while warning paying for the pledges “in what will likely be a tight fiscal environment … would require tricky trade-offs, and potentially either tax rises, or cuts to at least some other areas of public spending”. It added that the stated aim of not increasing income tax alongside plans to cut business rates “could make this an especially difficult circle to square”. The manifesto also says pilot work will begin on proposals that ultimately exceed the powers of the Holyrood parliament, including the provision of a minimum income guarantee for all, building on exploratory work undertaken in the last parliament on a citizens’ basic income. There are also plans to establish a £10m fund to allow companies to pilot the transition to a four-day working week, while an SNP government would continue to call for the devolution of employment law. A number of new policies are based on learning from New Zealand, such as offering women who have a miscarriage or stillbirth and their partners three days of paid bereavement leave, and a school leavers’ toolkit to equip young people with practical skills like budgeting and financial literacy. On transgender rights, reform of which proved hugely controversial in the last term, resulting in two consultations and no legislative progress, the manifesto states: “We remain committed to making necessary changes to the Gender Recognition Act.” Sturgeon said she still believed Scotland should aspire to best international practice – which has been established as the process of self-identification, which some women’s groups have raised concerns about – and said she was not proposing a third full-scale consultation. “But given how polarised this debate has become, in a way that has been harmful particularly to trans people, then I think some period of discussion, of transparency with women, with human rights and equality groups, to look at exactly what do we need to do to reform this legislation would be sensible.” Pressing home her “both votes SNP” message, after the advent of Alex Salmond’s Alba party raised questions about whether voting for an alternative on the regional list might increase the number of pro-independence MSPs returned, Sturgeon said: “The Holyrood voting system means Scottish parliament election results are always on a knife-edge. That’s hardwired into the system. So every vote really does matter.”