Thousands of angry Westcountry workers will be taking to the streets of the capital on Saturday to show their opposition to austerity measures.
The March for a Future That Works aims to protest against the Government's spending plans and call for fresh thinking on getting the economy growing.
The event, backed by the TUC, is expected to attract tens of thousands of people into London and it is being billed as one of the biggest protest marches of recent times.
Nigel Costley, regional secretary of the South West TUC, said people were angry about austerity.
"The impact of spending cuts and the government's obsession with austerity economics is hitting families hard in communities right across the South West, with 90 public sector workers in the region losing their job every day since the coalition took power," he said.
"Life has become unbearably difficult for many people, especially those who have come to rely on essential public services which are now being cut back or axed, and households where a family member is without any or enough work.
"Austerity is failing and nowhere is this more visible than the plight of the million plus youngsters who are desperate for work but find themselves hunting for jobs in the toughest jobs market for a generation."
According to unions, the march comes at a "dire time" when one million young people are out of work, wages have stagnated and welfare cuts are hitting many low paid workers, forcing more people to borrow to get by.
They say unrelenting austerity measures have failed to ignite growth and as a result people in the UK have witnessed the longest decline in living standards for generations.
The Unite union, which is supporting the march, is calling on the Government to take immediate action through increasing the minimum wage by £1 an hour, to help low earners and stimulate the economy.
Laurence Faircloth, Unite Regional Secretary in the South West, said a strong turnout from the region was expected.
"The number of people pledging to attend from the South West has been fantastic," he said. "But we want as many people as possible marching in London on October 20 to send a clear message to the Government – austerity isn't working and we need an alternative that gets the South West economy growing."
Mr Faircloth said he talked to members on a daily basis and a growing number were struggling.
"People are being hit hard by the government's reckless policies and living standards have plummeted as a result. Yet the coalition continues to press ahead blindly with their failed austerity plan, which is pushing borrowing up, rather than bringing it down."