CPI annual inflation was 4.5% in April, putting it back on course after the March reading of 4.0% showed a 0.4% fall on February.
The last time CPI annual inflation was higher was September 2008, when it stood at 5.2% – the record high for CPI.
The Office of National Statistics said the largest upward pressures to the change in CPI inflation came from transport, where the timing of Easter contributed to fares rising by 29% between March and April 2011.
However, Jeremy Cook, chief economist at World First, said the jump in the core consumer price measure to its highest level since 1997 discounts transport factors away.
He said: “This solidifies the Bank of England’s view in last week’s quarterly inflation report, which suggested CPI will likely hit 5% soon and leads us to believe a rate rise in August is now more likely than ever.
“We expect tomorrow’s minutes from the Bank of England meeting will show the five members of the MPC who are still sitting on the fence will now start leaning towards hikes.”
