Salmond to say independent Scotland would champion welfare state and NHS, and thus help revitalise the centre-left in England

Alex Salmond is to throw down a provocative challenge to his opponents in London by claiming that an independent Scotland would offer English voters a model for a more socially just and tolerant society.

In the annual Hugo Young lecture for the Scott Trust, the owners of the Guardian, the first minister will argue that Scotland is already more socially liberal than the rest of the UK and would become a "beacon of progressive opinion" for voters elsewhere in the British isles.

An independent Scotland would champion the welfare state and health service, helping the centre-left in England revitalise itself and eventually topple the Tories and Liberal Democrats from power, Salmond will tell an audience in London.

In his first major speech since confirming he will stage an independence referendum in autumn 2014, he will raise Scotland's smoking ban, free university tuition, free prescriptions and his attempt to set a minimum price for alcohol as examples of Scotland's differing approach.

"An independent Scotland can be a beacon for progressive opinion south of the border and further afield – addressing policy challenges in ways which reflect the universal values of fairness and are capable of [being implemented] within the other jurisdictions of these islands, and beyond," Salmond will say.

"That, I believe, is a far more positive and practical Scottish contribution to progressive policy than sending a tribute of Labour MPs to Westminster to have the occasional turn at the Westminster tiller."

In a momentous week for his Scottish National party government in Edinburgh, Salmond will publish a detailed consultation paper on the mechanics of the referendum on Wednesday afternoon, officially setting in train the biggest constitutional challenge for the UK in centuries.

The Scottish government's confidence about the surge in public approval for independence to as high as 40% in Scotland, suggested by a series of opinion polls since the new year, will be dented by the latest Guardian/ICM poll, which shows a 63% to 30% majority in Scotland against independence, albeit with a small sample.

Provoked by an unexpected attack by David Cameron, Salmond disclosed for the first time earlier this month that he plans to stage the referendum in the autumn of 2014, in advance of the next UK general election.

Salmond is close to accepting Cameron's offer of a deal to make the referendum legally watertight after the UK government's lawyers said Salmond did not have the legal authority to stage the poll without Westminster's approval. Salmond is due to begin detailed talks on that deal with Michael Moore, the Scottish secretary, later this week.

While he is expected to accept Cameron's call for the referendum to be run by the UK Electoral Commission, Salmond will continue to vigorously resist the prime minister's demands that it ask just one "yes or no" question on independence.

Salmond will also confirm that he would welcome a second question on increasing Scotland's tax-raising and legal powers while remaining in the UK to be added to the referendum, in addition to his main question on independence.

Polling suggests a majority of Scots support "devolution plus" or "devo max", rather than full independence.

Salmond's provocative attacks on the UK government and the Labour party during the Hugo Young lecture are likely to increase tensions between Edinburgh and London, and fan the flames of resentment amid growing claims in England that Scottish government spending is subsidised unnecessarily by UK taxpayers.

Salmond will try to defuse that attack by blaming his political opponents for refusing to adopt welfare measures similar to those in Scotland. He will state: "We have made a conscious decision to provide certain core universal services, rights or benefits, some of which are no longer prioritised by political leaders elsewhere in the UK – such as free university tuition, no prescription charges, and free personal care for the elderly."

In Tuesday's speech, Salmond will recall that he was given an ecstatic welcome in Liverpool last year by some members of a BBC Question Time audience when he repeatedly attacked the UK government's NHS and welfare reforms.

"Perhaps the strongest support I got was when I made a plea to the audience not to let the three biggest Westminster parties destroy England's National Health Service – just one of many issues where the Westminster class are out of touch with the people of England," he will say.

"Looking at the chaos of health reform in England now, I thank the heavens that Westminster's writ no longer runs in Scotland on health issues. But the looming issue of welfare reform exemplifies why Scotland needs the powers to make our own policies to meet our own needs and values."

Salmond will also set out his belief that Scotland's independence will not threaten other parts of the UK but lead to a more mature relationship between equals, leading to a "social union" between Scotland and England, sharing a currency, monarchy and other institutions.

"On areas from energy grids to emergency policing requirements; from fisheries policy to defence co-operation; from telecommunications to transport links; Scotland will work with all our neighbours for a common good.

"But most of all, in addition to these institutional, cultural, economic and practical links, Scotland shares ties of family and friendship with our neighbours on these islands which never can be obsolete, and which will continue and flourish after Scottish independence."