A fifth of UK employers have borrowed to close a deficit in their pension schemes, according to a study by Mercer Human Resource Consulting. The findings come as Royal Mail, the UK postal service, warned it could need more than £6bn ($10bn) to meet its pension fund's obligations.

Almost 20% of companies have either issued debt or taken additional bank loans to reduce their pension scheme deficit, according to a poll of chief financial officers and treasurers at the leading 350 companies in the UK.