Tax avoiders are 'sinful' and rising inequality is a national scandal that should be addressed by a voluntary top-up tax system, the Archbishop of York has said.

In an interview with the Guardian, John Sentamu said today that people who are willing to pay more tax towards health, education and social care should be able to do so through voluntary payments.

'Income inequality is the cause of all our trouble. Inequality leads to huge social problems,' he said.

Cases of scarlet fever, which recently hit a 50-year high, have illustrated growing inequality and malnutrition. Archbishop Sentamu said that the disease, which was a common cause of death in children in Victorian times, 'had been wiped out and is now re-emerging in poor communities. Hello, what is going on here?'

The archbishop expressed concern at a parliamentary report this week that found at least 1.3 million older people in the UK were at risk of 'withering away' from hunger and isolation.

Meanwhile, an Oxfam report showed that 42 individuals in the world hold as much wealth as the 3.7 billion people who make up the poorest half of the global population, and that nearly three-quarters of people in the UK want the government urgently to address the income gap.

In his Guardian interview, Sentamu also pointed to a 2017 British Social Attitudes survey, which found that 48 per cent of respondents favoured higher taxes to pay for more spending on health, education and social benefits, while only four per cent said they wanted taxes to be cut, and 44 per cent said tax rates should stay the same.

He said: 'If citizens are willing to pay more, there needs to be a mechanism to do so. I call it top-up...The government should say it would guarantee that these tax increases will go towards health, education and social care. There's no reason why it can't be done.'

Referring to the creation by the postwar Labour government of the welfare state to tackle want, disease, squalor, ignorance and idleness, Sentamu said: 'We need to go back to the idea of a social contract to slay the five giants.'

He also said that Britain's tax system needed 'rebalancing' to be more progressive, with higher earners paying more allowing 'some people at the bottom to be taken out of taxation altogether'.

He added: 'The government has got the mechanisms [to deal with tax avoidance], so they should do it. Some people are avoiding [paying tax] in big terms. Those people should be asking themselves: am I contributing to the misery of other people, to children being trapped in poverty, the increase in food banks?'

He described tax avoidance as 'sinful' and those who practise it as 'morally bankrupt'.

Referring to a 2009 book, The Spirit Level: Why Equality is Better for Everyone, by Richard Wilkinson and Kate Pickett, he said: 'You can only build a wall if the spirit level is absolutely straight. At the moment, our spirit level is going the other way, so our walls aren't straight, and all our attitudes, our behaviours, our cultures are warped. The book says we should not concentrate too much on growth at the expense of equality. More equal societies are happier societies.'

Sentamu also said that inequality and social exclusion in the UK had been graphically illustrated by the Grenfell Tower fire disaster last summer, in which 71 people died.

'If every stone is not turned, if justice is not seen to be done, you will not get reconciliation. People will remain angry,' he said, referring to the community in north Kensington.

Sentamu, who was an adviser to the public inquiry into the murder of the black teenager Stephen Lawrence, said he was not worried about how long the Grenfell Tower public inquiry might take, 'but I am worried [about] whether this inquiry is going to turn every stone. The jury's still out.'

He said that the government should be urgently and actively intervening to ensure that Grenfell survivors and members of the community could rebuild their lives.

'The government should see this as the terrible disaster it is and create a Marshall Plan,' he added, referring to a billion-dollar initiative to rebuild European economies after the second world war. 'We need to move very, very fast.'

Sentamu further criticised the government for not implementing the 2014 recommendations of the Living Wage Commission, which he chaired. Instead, the government had merely topped up the minimum wage for over-25s 'and then had the audacity to call it the living wage. It isn't.'

The 'national living wage' is set at at £7.50 per hour, whereas the Living Wage Foundation's figures are £8.75 across the UK and £10.20 in London.