Final salary pension schemes have dug deeper into debt in recent weeks as share prices have fallen further, according to the latest reading from the Pension Protection Fund, which insures the retirement benefits of insolvent employers.

The total shortfall of 6,468 schemes in deficit rose to £122.1bn in October from £113.5bn in September and from £36.9bn a year earlier. The sharp rise in the deficit in October illustrates the swingeing impact of sharp falls in stock markets last month and is likely to fuel the debate about what measures pension schemes should take to limit their exposure to volatile assets.