Nicola Sturgeon has pledged to pay every NHS and social care worker in Scotland a £500 Covid bonus and has called on Boris Johnson to make the payment tax-free. In a speech to the Scottish National party’s annual conference that sought to link the recovery from the pandemic with the push for independence, the first minister said health and social care workers deserved special recognition for the “incredible” sacrifices they had made. Sturgeon added to repeated attacks on Johnson’s government in her speech on Monday by urging the prime minister not to tax the bonus, arguing that Holyrood’s income tax powers were too limited to do so. Implying that this was a test of Johnson’s compassion, she said: “We are asking nothing of the UK government – with this one exception. Please allow our health and care heroes to keep every penny of Scotland’s thank-you to them. Do not take any of it away in tax.” Scottish government officials said the pledge would cost about £180m and would cover 391,000 full-time and part-time NHS and social care staff, including students who volunteered to help during lockdown, GP surgery staff and palliative care workers, as well as their employers’ share of staff national insurance contributions. Sturgeon’s aides said they did not know whether the UK tax system allowed one-off bonuses to be made tax-free and were not aware whether it had been done before. One said it was down to the prime minister to confirm whether he liked the proposal, before working out the logistics. The Treasury said any income tax levied on the £500 bonus would be collected by the Scottish government, so Sturgeon could increase the bonus to cover the tax lost, and then eventually recoup that via increased tax revenues. “The income tax on these payments is paid to Scotland, not Westminster – and the Scottish government has the powers and funding to cover the tax owed on the payment if it wishes,” a spokesman said. The first minister also unveiled other funding pledges: £100m to help the poor and vulnerable over winter, including a £100 one-off payment to families whose children get free school meals; and new funding for apprenticeships, including a £100-a-week apprenticeship bonus for school leavers under 18 and £5,000 to firms for each new apprentice they hire. The Scottish Conservatives argued that these schemes used £9.2bn in record extra funding from the Treasury to the devolved government to tackle the social and economic impacts of the coronavirus pandemic. About £1bn of that has not yet been accounted for in Scottish government budgets. “This was a series of SNP promises brought to you by [the chancellor] Rishi Sunak’s spending,” said Douglas Ross, the Scottish Tory leader. Sturgeon said, however, that the policies were evidence of Scotland’s socially conscious and inclusive ethics in a speech that mentioned Johnson by name five times and Brexit eight times. She said the Covid crisis had proved there was a gulf between the UK and Scottish government’s outlook and attitude, strengthening the case for independence. She deflected demands from many SNP activists for headway on a fresh referendum, however, asking voters for their authority in next May’s Scottish election to call for one “in the early part of the next parliament”. “If we want to make sure the country we rebuild is the one we want it to be, with kindness, compassion, fairness, equality and enterprise at its heart, and not one built in the image of Boris Johnson and his band of Brexiteers, we must work to the right plan, with all the tools we need to do the job,” she said. “Independence is not a distraction from the task of post-Covid reconstruction. It is essential to getting it right.” Richard Leonard, the Scottish Labour leader, said: “This sum announced by Nicola Sturgeon will not make up for the years of pay restraint and austerity that staff in these sectors have had imposed on them by Tory and SNP ministers.” As many care staff were part-time, their pro rata bonus would be “derisory”, he added.