Teachers are more than £5,000 a year worse off in real terms compared with 2010 as a result of the public sector pay squeeze, according to analysis by Labour.
Shadow education secretary Angela Rayner said the failure of average wages to keep up with inflation had contributed to a crisis in teacher recruitment and retention.
According to Labour's analysis, if wages had risen in line with CPI inflation, the mean salary paid to teachers in England would have risen from £34,800 in 2010 to almost £40,500 in 2016 instead of the actual figure of £35,100.
Ms Rayner said: "It is no surprise that schools are facing a crisis in teacher recruitment and retention when the government has handed teachers a real-terms pay cut year after year.
"These stark figures show that the average teacher is now thousands of pounds worse off than they were in 2010, and the government's plans to continue with the public sector pay cap will only make matters worse."
The 1 per cent cap on pay increases is set to take the mean average salary for 2017 to £35,451 whereas inflation-linked rises would mean a £41,470 wage.
Chris Keates, general secretary of the NASUWT union, told the Observer that teachers were struggling to make ends meet.
"The latest statistics indicate that more than a quarter are having to rely on credit cards, overdrafts and payday loans to make ends meet every month, and many new and recently qualified teachers are unable to afford to rent or buy a home," she said.
"To continue to provide high-quality public education for every child, we need a teacher workforce which is competitively remunerated and to restore teaching as the profession of choice for UK graduates."
A Department for Education spokesman said: "There are now more teachers in our schools than ever before - 15,500 more since 2010.
"Overall the number of new teachers entering our classrooms outnumbers those who retire or leave.
"We take teacher recruitment very seriously which is why we are investing £1.3 billion up to 2020 to continue to attract the best and brightest into teaching and have given headteachers freedom over teacher pay, including the ability to pay good teachers more."
Officials pointed out that teachers had benefited from the repeated increases in the personal allowance, handing an income tax cut of more than £1,000 to a basic-rate taxpayer.