The ex-Labour leader joined the campaign trail in Greenock today where he praised the "defiance and unity" shown in the aftermath of the Manchester terrorist attack, insisting the city has become a "global symbol" of courage.
But he also said it was "essential" for Scots to elect Labour MPs ready to fight for social justice as the country will be among the areas worst affected in the UK by fresh austerity cuts.
Almost 45 per cent of the British population - 23million people - will be poorer, and on average their households £1,000-a-year worse off, by the start of the next decade, according to the Institute for Fiscal Studies figures, Mr Brown said. He warned that the Tories, if triumphant on June 8, will continue hurting families completing a ‘decade of decline’ with no end in sight to their slashing of the value of tax credits and child benefits.
The cuts and a raft of other Tory policies are set to leave 15.7million British people - one quarter of the entire population - living in poverty by the end of the next parliament, Mr Brown added.
Mr Brown said: "Wages will be rising more slowly than prices - especially for nurses, teachers, carers and others among five million public sector workers, who will see only a one per cent rise in wages while prices rise much faster.
“Areas facing job losses such as Wales, the North and Scotland will feel it even more acutely. We are a nation where the Tories are creating living standards stagnation."
He added: "The Tories talk about uniting the nation but rising poverty and worsening inequality will leave us more economically polarised and socially divided under Theresa May than at any time in living memory.
“The claim that her government is about helping mainstream Britain is undermined by the stark future of declining living standards ahead for the majority of people.
“The mainstream is being marginalised as the majority see their living standards fail to rise, or for millions, fall significantly.
“That’s why it’s essential to elect Labour MPs who get up in the morning to fight for social justice and will be voices for the mainstream - the middle and lower income Britain that is being hardest hit.”
The former Prime Minister also paid tribute to those affected by the terrorist attack in Manchester last week.
“Hearts have been broken but our resolve remains unbreakable," he said.
“Lives have been destroyed but our spirit is indestructible.
“They may think we are vulnerable but our strength of shared purpose makes us invulnerable.
“In the hours and days following the attack Manchester has become a worldwide symbol of courage, defiance and unity.