Britain has suffered a 'relentless rise' in the number of working families struggling to make ends meet over the last five years, according to poverty campaigners.
The Joseph Rowntree Foundation said there were now half a million more children trapped in poverty than five years ago.
Its report, UK Poverty 2018, says 14.3 million people – more than one in five of the UK population – are poor.
Of these 8.2 million are working-age adults, 4.1 million are children and 1.9 million are pensioners.
The foundation says the rise is driven by a range of factors including parents getting trapped in low-paid work with little progression and changes to tax credits and benefits that top up low wages.
The foundation's chief executive, Campbell Robb, said: 'We are seeing a rising tide of child poverty as more parents are unable to make ends meet, despite working.
'This is unacceptable. It means more families are trapped in impossible situations: struggling to pay the bills, put food on the table and dealing with the terrible stresses and strains poverty places on family life.
'It’s time for us to decide what kind of country we want to be. As we leave the EU, we must tackle the burning injustice of poverty and make Britain a country that works for everyone.'
Cllr Anntoinette Bramble, chair of the Local Government Association’s Children and Young People Board, said: 'To tackle the issue, including the worrying growth in in-work poverty, government needs to resource and fully engage with councils to prevent homelessness and support people into jobs to lift themselves out of poverty.
'Welfare reforms also need to be adapted to reduce the risk of homelessness and councils need more powers to build more affordable homes.'