A government report has backed a new national pension system that is designed to encourage employees to save.

The personal accounts system, to be launched in 2012, will top up payments from the basic state pension and will use automatic enrolment to persuade millions of workers to save.

The government's report has claimed that almost everyone will benefit from entering the scheme, and that over 70% of savers will more than double their initial outlay into the scheme.

"Even after inflation, virtually everyone can expect to get back more than they put away," said Rosie Winterton, the minister for pensions and the ageing society.

However, the Pensions Policy Institute (PPI) has called the government's figures into question.

"This finding is based on a specific set of assumptions which may, or may not, transpire in the real world," said Niki Cleal, director of the PPI.

"All individuals who save in money purchase pension schemes are exposed to the risk that the value of their pension pot can go down as well as up."