British workers are suffering the longest and severest decline in real earnings since the mid-Victorian era, according to new analysis.

Research carried out by the TUC suggests that the UK would have to go back to the 1860s for a pay squeeze as deep and as long as the current one. This year is the seventh consecutive year of falling real earnings for UK workers, the TUC claims, a situation, it says, that has no historical precedent. The body, which represents 6 million workers, calculates that there has been an 8% fall in real earnings between 2007 and 2014.

The findings come as tens of thousands of people from across the UK prepare to march in London next Saturday as part of Britain Needs a Pay Rise, a TUC-organised rally. Unions complain that the lowest paid and the “squeezed middle” are bearing the brunt of the economic recovery. “Living standards today might have improved dramatically since the late 19th century, but workers in 2014 are now into the seventh year of falling real wages and their financial pain is real, with no end to overstretched household budgets in sight,” said the TUC general secretary, Frances O’Grady.

Historians claim that not since 1865-67 has there been a comparable squeeze on earnings for British workers. Back then, falling wages were triggered by financial liberalisation that saw the failure of the largest joint stock bank and led to public protests, resulting in the extension of the vote to more than a million working people and the TUC’s founding.

Other notable declines in real wages include the global depression of 1874-78, the austerity years of 1921-23 that prefigured the UK’s disastrous return to the gold standard in 1925, and 1976-77, as the economy came out of recession. However, the declines in each of these crises lasted only two to four years, compared with seven years this time. The TUC analysis shows the current pay squeeze is twice as deep as the worst of these episodes, at 8.2%, compared with 4% in the 1920s. The TUC has been quick to draw parallels between the past and the present day. “The huge squeeze on pay being felt by families up and down the country is the longest and deepest experienced since records began in the 1850s,” O’Grady said. “Back then most people didn’t have the vote, small boys were still being sent up chimneys, and the poor lived in fear of ending their days in the dreaded workhouse.”

Anger over falling wages, which unions blame on a recession triggered by the banking crisis of 2008, will see an estimated half a million NHS workers across England and Northern Ireland take strike action tomorrow. NHS members of unions including Unison, Unite, the Royal College of Midwives and the GMB will strike between 7am and 11am. They are protesting at the government’s decision to ignore the recommendation to award them a 1% pay rise made by the independent pay review body.

“In 1865 the UK economy had taken a nosedive following reckless financial speculation in the City and the collapse of a major bank, not dissimilar from the events of 2008,” O’Grady said. “But although pay fell in real terms in that slump of almost 150 years ago, the squeeze on pay that hit Victorian workers only lasted two years.”