Inflation hit a three-year high of 5.2% in September, thanks largely to price hikes from the UK's biggest energy providers.

That's according to data from the Office for National Statistics (ONS), which showed that consumer price index measure of inflation had risen dramatically from 4.5% in August. As state benefits are linked to September's CPI figures, the government will be forced to pay out a pretty hefty sum in additional welfare.

However, the increases are lower than those the government would have had to face had they not changed the rules earlier this year. Earlier this year the coalition courted controversy by changing the measure it uses to effectively 'inflation-proof' benefits payments.

Before this year, benefit increases had been automated using the usually-higher retail price index (RPI) - which rose to 5.6% last month - its highest level in 20 years - according to today's figures. As a result of this seemingly minor change, the government estimates that it will be able to save itself £11 billion a year by 2015-16.

TUC general secretary Brendan Barber said: "Today's figures also confirm that the government's CPI stealth cut will reduce the value of benefits and pensions by 0.4% next year. This cut could slash public sector pensions, as well as many in the private sector, by nearly 30% over the next three decades, and send many more people into poverty in retirement."