It is relatively easy to work out what that means with a DC scheme: the employer simply pays a proportion of its payroll into it each year.

ECONOMIST: Pensions rules get complex again

The BBC's chief political correspondent, Norman Smith, said Treasury officials were trying to work out a definition of the rules surrounding eligibility for the mortgage guarantee scheme that allowed parents to buy a home for their children but not to buy a holiday home.

BBC: Budget 2013: Row over 'second home subsidy'