The average annual pension paid through the Teachers’ Pension Scheme (TPS) has fallen by more than 10 per cent in the past 20 years, according to a new report.

The report by the National Audit Office into public service pensions shows that the average annual pension for a retired teacher in 1999-2000 was £13,679, which is worth £23,546 today (according to the Bank of England inflation calculator).

However, the average amount paid to teacher pensioners last year was £12,337, the report reveals.

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The report also shows that average teacher contributions per year have increased by 33 per cent in the past 20 years - from £2,275 in 1999-2000 to £3,438 last year. However, in real terms, that is a decrease of £534.

The report states that public service pensions, including the TPS, have become “more expensive” over time as more members enter retirement and live longer.

And it shows that further cuts are in the pipeline, with public service pension schemes set to take up just 1.5 per cent of GDP by 2064 compared with 2 per cent today.

Kevin Courtney, joint general secretary of the NEU teaching union, said: “It is clear that the government’s cuts to public service schemes have gone too far.

“Public service pensions have always been affordable. As the NAO makes clear, the vast majority of the increase in the amount paid is due to the increase in the number of public service pensioners, which is a known demographic consequence of the baby boomer generation reaching retirement.

“The average pension paid in the Teachers’ Pension Scheme has actually fallen since 1999-2000 from £13,679 to £12,337 today.

“The correct way of looking at public service pension costs is as a percentage of GDP. Public service pensions are affordable now at around 2 per cent of GDP, but are due to fall to 1.5 per cent of GDP by 2064-65. There is no justification for further politically motivated attacks on public service pensions.”

It shows that, compared to the other three largest pay-as-you go public sector pensions schemes (those covering the armed forces, NHS and civil service), teachers receive, on average, the highest annual pension payments.