The government has been urged to abandon planned rises in national insurance that is claimed would cost 57,000 jobs.
The centre for economics and business research (cebr) calculates that a 0.5% rise planned for April 2011 would lead the loss of 57,000 jobs.
The centre argues that the increase would be counter productive as it would cost the Treasury around £990m in extra benefits, while raising only a small amount of additional taxation.