The National Employment Savings Trust (Nest) has called for the limit on contributions into its scheme and the ban on transfers in and out to be scrapped.
In its submission to the government's consultation on a lifting of the restrictions, Nest said that removing them would remove an administrative burden for employers and allow more freedom for Nest savers.
'Nest's restrictions complicate the decision-making process of medium-sized employers, many of whom will experience a private pensions sector already busy supporting other clients and who will therefore look to Nest as a potential provider,' said Nest chief executive Tim Jones (pictured).
'Removing the restrictions will help us help those employers to get the job done.'
Nest's contribution limit is set at £4,400 for 2012/13, and is set to be adjusted annually in line with average earnings.
Pensions minister Steve Webb has consistently argued that legal barriers could stand in the way of lifting the restrictions on Nest. He has claimed the move could contravene European Union laws, and argued it could open up the government to legal challenges from providers. Giving evidence to parliament's Work and Pensions Committee last month he said the government would need to prove the pensions market was failing as a result of Nest operating with the restrictions if they were to be lifted.
However, Labour has dismissed Webb's concerns, accusing him of dragging his feet over the issue.