Chancellor George Osborne will defend his 81 billion pounds UK spending cuts later amid Labour claims that they are reckless and will hit some of the poorest hard.The independent Institute for Fiscal Studies has also said the cuts may not be enough if the budget deficit turns out to be worse than feared. The UK faces its biggest spending cuts for decades over the next four years.The government says that changes to tax, benefits and public services will mean the richest contribute the most.Mr Osborne told MPs yesterday that he had acted to restore sanity to our public finances and deal decisively with Britain's record peacetime deficit. The government says public debt interest repayments now total 120 million pounds a day.Hours after Mr Osborne's speech crowds of demonstrators gathered outside Downing Street to protest against the cuts, which the TUC has said will have a devastating social impact.