Workers with degrees earn more in private firms than in the public sector, while the opposite is true for staff with lower level or no qualifications, according to a new report.
The TUC said its analysis showed that people educated to degree level earned 4.7% more than public sector workers with the same level of qualifications, while employees without any qualifications earned 3.2% less in the private sector.
Public sector employees were almost twice as likely to have a degree as those in private companies, with jobs in the civil service and NHS such as physiotherapy and radiography, increasingly requiring high level qualifications, said the union organisation.
The study also revealed that workers often have their pay cut if their job is outsourced from the public to the private sector, despite regulations aimed at protecting their conditions.
TUC general secretary Brendan Barber said: "The anti-public sector brigade has been guilty of some pretty misleading claims on public sector pay. The fact is that most public and private sector jobs are completely different and overall pay comparisons are meaningless, but it won't stop people using them to attack the pay of nurses, teachers and home care workers.
"It is true that pay and benefits are fairer in the public sector, with all employees entitled to the same staff pension schemes and the gap between the highest and lowest-paid far smaller than in the private sector.
"While high-flyers with degrees can expect to earn less in the public sector, lower-skilled and lower-paid staff can expect a better deal in the public sector.
"For small-state fanatics to get their wish and bring the public sector into line with the private sector, the Government would need to cut the wages of the poorest public sector workers and give huge pay rises to those at the very top. That kind of reform is unlikely to get much support from taxpayers."
The report was published a week before the planned strike by public sector workers over pensions, which is set to involve over two million people.