A YouGov poll published on Saturday to coincide with the TUC's March for the Alternative in London asked, 'Generally speaking, do you support or oppose the aim of the march to campaign against public sector spending cuts?'
The majority (52%) said yes, with one in three (31%) disagreeing. One in five Conservative voters backed the aims of the march.
Speaking on Saturday, Brendan Barber (pictured), general secretary of the Trades Union Congress, said: "No part of our public realm is to be protected.
"And don't believe it when ministers say that the NHS is safe in their hands. With over 50,000 job cuts already in the pipeline - nurses, doctors, physios, midwives - in the name of so-called efficiency savings of £20 billion, the NHS as we know it is already in intensive care.
"With David Cameron talking about selling it off to 'any willing provider' out to make a profit, the NHS is facing the gravest threat in its history.
"Today let us say to him: we will not let you destroy what has taken generations to build.
"Let's be brutally clear about these brutal cuts. They're going to cost jobs on a huge scale, adding to the misery of the 2.5 million people already on the dole.
"They are going to hammer crucial services that bind our communities together. And they're going to hit the poorest and the most vulnerable hardest.
"The Government claims there is no alternative. But there is. Let's keep people in work and get our economy growing. Let's get tax revenues flowing and tackle the tax cheats. And let's have a Robin Hood tax on the banks, so they pay us back for the mess they caused."