Firefighters, teachers, nurses and office workers from all over Scotland marched through Glasgow alongside students, anti-war protesters and union members in a passionate demonstration against the austerity measures.
More than 4000 people attended a rally in the city's George Square then marched to Glasgow Green, waving banners and chanting their opposition to school closures, job cuts and a lack of funding for the NHS, and calling for policies which promote growth.
The rally was organised by the Scottish Trades Union Congress (STUC), and included disabled former Remploy workers who lost their jobs when the Government-owned factories were closed.
Similar events were held in Belfast and London, with union leaders saying they will call for a general strike to be held as soon as possible after yesterday's protests.
In Scotland, much of the crowd's ire was focused on the government at Westminster, with the Coalition being blamed for driving down living standards and making thousands of people unemployed through their "obsession" with austerity.
But the Scottish Government also came in for criticism, with Grahame Smith, general secretary of the STUC, saying that SNP ministers "could not hide behind [Chancellor] George Osbourne".
He said: "We believe that there's more that they can do with the powers they have to support investment and get people back to work.
"They should stop putting the blame on the constitutional situation and use the powers they have."
He added that Labour should abandon their own policy of delaying cuts to public funding, which he branded "austerity light".
Smith said: "We're not looking for more of the same, we're looking for a radical change of direction. We need investment in jobs and decent public services."
Reverend Sally Foster-Fulton, convener of the Church of Scotland's Church and Society Council, also addressed the rally on the need for a change of direction from government.
She said: "I think we've got it wrong in a lot of ways – our economy is upside-down. If society is ultimately here so that we can look after each other, then surely we have to put those with greatest need at the head of the queue.
"If we want world-class universities, if we want a massive increase in renewable energy, if we want to offer a helping hand to those in need, it doesn't come for nothing and we need to get our priorities right."
Student leader Robin Parker, president of the NUS, hit out at cuts to funding for Scotland's colleges, saying campus budgets were being slashed for the second year in a row.
He said: "Students are standing side-by-side with trades union and community members from across Scotland today because we don't want to see Westminster's austerity policies dump an entire generation on the scrapheap.
"This year, we will mobilise, we will campaign, and we will win. Students won't stop campaigning until these cuts stop. Lecturers won't stop campaigning until these cuts stop.
"Everyone here today in George Square won't stop campaigning until the cuts stop. We won't stop until we have a future that works."
Derek Thomson, chairman of the Scotland committee of public sector workers' union the PCS, said: "We want a future funded through fair and progressive taxation and one that delivers public services and welfare benefits to those that need them.
"We want investment in jobs that builds both the public and the private sectors. That's what PCS members are marching for, and politicians across the UK would do well to listen."
In London, Labour leader Ed Miliband was among dozens of speakers at a rally in Hyde Park, joining union officials who spoke of the impact of spending cuts on public services.
HE dubbed the Prime Minister "clueless" as he joined more than 100,000 people at the demonstration. He said the coalition was cutting taxes for millionaires and raising them for everyone else.
Miliband said: "It is one rule for those at the top and one rule for everyone else."
The Labour leader was booed by a small section of the crowd in Hyde Park when he said the party would have to make "hard choices" if it was in government.
He pledged that if he became prime minister he would tax bankers' bonuses, support the building of 100,000 houses and end the privatisation of the NHS.
Bob Crow, leader of the RMT rail union, was loudly cheered when he called for a 24-hour general strike.
He also called on Miliband to oppose all spending cuts.
ON THE MARCH IN GLASGOW
Davey Blackie, youth worker, from Dufftown, Moray:
"I came on the march for a lot of reasons. We have to show some kind of resistance to services being cut back across the country. We're living with the failure of capitalism. I work with young people and you can see the effects the cuts are having on them, with a lack of opportunities or services to support them."
Morvern McLaughlin, student, 16, from Kilmarnock:
"I'm on the march because young people need to make a stand against what's happening. I want to see a strong NHS and have good schools around for when I have children. I see all these things being cut back and I am worried for the future."
Kaila McCulloch, mother-of-two from Shetland, works in the local authority valuation department:
"I think families are being stretched with higher food and fuel bills even when they have jobs, and wages coming in. We need investment to ensure that there is employment and decent housing for people – not cuts to services that everyone needs."