Prudential has maintained annual bonus rates on its Pru and Scottish Amicable with-profits policies and says policyholders have seen returns of 5 to 8 per cent over the past year.

Total bonus rates have been maintained or increased on all unitised plans, and a typical 25-year £50 per month Prudential mortgage endowment maturing in 2015 will have increased in value by up to 10.1 per cent in its final year.

The insurer says it added around £1.9billion to with-profits policy values in 2014 of which two-thirds was in final bonus pay-outs.

It estimates annualised returns over the life of policies at between 4.5 per cent (10-year bond) and 6 per cent (20-year bond) with the Scottish Amicable 25-year savings endowment showing 5.5 per cent.

The 10-year gross cumulative return of the with-profits fund is 109.5 per cent, just above the 107.6 per cent total return of the FTSE all-share index.

Aki Hussain, chief financial officer at Prudential UK & Europe, said: "Despite continuing economic uncertainty and interest rates being at an all- time low we have maintained our annual bonus rates for this declaration, further proof that investing in a strong with-profits fund can produce good returns for the cautious investor."

He said a significant increase in sales of with-profit bonds in 2014 reflected the rising demand from customers looking to protect themselves against market conditions.

Ned Cazalet, of Cazalet Consulting, said: "Careful liability management coupled with an impressive track record for astute asset allocation has enabled Prudential to maintain solid financial strength at the same time as consistently delivering top flight investment returns to enhance the market-leading payouts enjoyed by its UK with-profit policyholders."