Anti-poverty campaigners and civil servants will stage a demonstration in Westminster while the Budget is being discussed by MPs, to protest against job and spending cuts and tax avoidance.
Members of the Public and Commercial Services union (PCS) will be joined by War on Want members for a march and rally opposite Parliament.
PCS leader Mark Serwotka said: "The latest inflation figures are another timely reminder that, beyond the bubble of privilege inhabited by Chancellor George Osborne and other millionaire Cabinet members, real people's living standards are under severe pressure.
"In these circumstances it is both vindictive and dangerous of the Chancellor to drive our economy even further down, in a race to the bottom where public services are handed over to big businesses to rake in huge profits and hard-won employment rights are eroded to make it easier to victimise and sack workers.
"Instead of setting his sights on those who everyone now accepts did nothing to cause the recession and the budget deficit, Osborne should go after the real scroungers - the tax dodgers who deprive our public finances of tens of billions of pounds every year and the corporations who are hiking their prices above inflation and profiting from hardship."
Simon McRae, senior campaigns officer at War on Want, said: "If George Osborne wants to help people most in need through his Budget he should crack down on the corporations and millionaires who dodge their tax obligations.
"While these dodges cost Britain up to £120 billion a year, many are facing savage cuts in public services and jobs. It is high time the Government ended this scandal."