The Government must not make a u-turn on its plans to start automatically enrolling all workers into a pension from next year, the National Association of Pension Funds (NAPF) has warned.

In a letter to George Osborne ahead of his Autumn Statement, the NAPF expressed alarm that the Government may be considering exempting small businesses from the reforms, or that it might delay its implementation for some or all employers.

With 14 million people set to have an inadequate income in retirement, the NAPF urged the Government to stick with the existing reforms and timetable, which could help up to nine million people save for their old age. It added that, under the current plans, auto-enrolment will be gradually phased in to help ease the transition.

From next year employers will be required to enrol people over 22 and earning a minimum of £7,475 per annum into a workplace pension. The Department for Work and Pensions estimates that this will get up to nine million people to saving into a pension for the first time, or get them saving more.

Last month it emerged that the confidential Beecroft report commissioned by Downing Street recommended that auto-enrolment be delayed for small companies.

As things stand, small employers will only be required to auto-enrol people into a pension from 2014 and pensions contributions will be phased in gradually to limit the impact on employers.

According to the Department for Business, Innovation and Skills small employers with between one and 49 members of staff employed 7,080,000 workers in the UK in 2010.