Unions will on Friday attempt to step up pressure on the nation’s rich by calling for the abolition of £25bn ($49.7bn) of tax breaks used by wealthy individuals and companies in “a new campaign for a fair tax system”.

The Trades Union Congress said its proposals would tackle “the growing gap between the super-rich and the rest of society”. Brendan Barber, general secretary, said: “This is not the politics of envy but the economics of fairness.”