(BBC): Prices are continuing to rise at their fastest rate for 40 years with food costs, particularly for bread, cereal and meat, climbing.
UK inflation, the rate at which prices rise, edged up to 9.1% in the 12 months to May, from 9% in April, the Office for National Statistics (ONS) said.
Fuel and energy prices are the biggest drivers of inflation, but the ONS said food costs had pushed it up further.
Workers and unions are pushing for pay rises to cope with higher prices.
But the government has warned against employers handing out big increases in salaries over fears of a 1970s style “inflationary spiral” where firms hike wages and then past the cost onto customers through higher prices.
Currently, inflation is at the highest level since March 1982, when it also stood at 9.1% and the Bank of England has warned it will reach 11% this year.
Inflation is the pace at which prices are rising. For example, if a bottle of milk costs £1 and that rises by 5p compared with a year earlier, then milk inflation is 5%.
In a BBC-commissioned survey of more than 4,000 people, 82% said they thought their wages should increase to match the rising price of goods and services.
Households were hit by an unprecedented £700-a-year increase in energy costs in April, and fuel price rises in June mean it costs more than £100 to fill an average family car with petrol.
Rail workers walked out on Tuesday causing severe disruption, with further strikes planned for Thursday and Saturday in a dispute over pay, jobs and conditions.
The Rail, Maritime and Transport union is calling for a pay rise of 7%, while employers have offered a maximum of 3%.
Unison, which represents public sector workers, accused ministers of “living on another planet” over “talks of public sector pay restraint”.
“Under-pressure health, care, school and council services desperately need staff to be given a pay boost that matches runaway prices,” assistant general secretary Jon Richards said.
The biggest teachers’ union is also warning of potential industrial action over pay.
The National Education Union has criticised government proposals for a 3% pay increase for most teachers in England, and called for an “inflation-plus increase for all teachers”.
But Dominic Raab told the BBC’s Today programme: “We have got to stop making the problem worse by fuelling pay demands that will only see inflation stay higher for longer and that only hurts the poorest the worst.”
The ONS said rising prices for food and non-alcoholic beverages helped fuel inflation in May.
Russia’s war in Ukraine has severely restricted wheat and maize supplies, which are used to make bread and cereals, from two of the world’s biggest exporters.
Ukraine is also a major producer of of sunflower oil, meaning the costs of alternatives have also climbed.
Market research firm Kantar has forecast that the average annual grocery bill in the UK is set to rise by £380 this year.
Supermarket Asda told the BBC some shoppers are setting £30 limits at checkouts and petrol pumps, with customers putting less in their baskets and switching to budget ranges.