Workers in the UK face one of the sharpest income falls in the developed world when they come to retire, a report has found.

Within the UK, an average earner who relied just on the state for their pension income would get around 38% of what they had been earning as a wage - with only Chile and Mexico having steeper falls, the Organisation for Economic Cooperation and Development (OECD) found.

The OECD made the findings after examining the "net pension replacement rate" for average earners across 34 countries.

The replacement rate is the amount that people on average wages will end up with as a retirement income, as a proportion of their income when they were earning.

But if a UK saver makes their own pension provision, this can make a big improvement in terms of cushioning their retirement income fall, the report found. They c ould end up with an income equating to around two-thirds (67%) of the income they had during their working lives.

If someone did make their own pension provision in addition to what they can expect from the state, they would see a smaller fall in their income when they came to retire than average earners in countries including Australia, Sweden, Germany, Denmark and France, Switzerland, Norway and Finland, according to the findings.

Tom McPhail, head of retirement policy at Hargreaves Lansdown, said: "This analysis makes embarrassing reading for the politicians who have been responsible for the UK's pensions over the past 25 years."

He said that the automatic enrolment of people into workplace pensions, and the pension freedoms which were launched in April to give people aged 55 and over more flexibility over what they do with their pension pot, may help to engage people more with retirement saving.

He continued: "T he challenge now is to make sure the amount being invested into pensions is increased as quickly as possible."

The OECD warned that in general, future generations are likely to find their pension entitlements much less generous than they are now and many may face a serious risk of pensioner poverty.

Many current pensioners, at least men, have worked for most of their lives often in rather stable jobs. But a job for life or even an intermittent career might not be the norm for people starting out today, the Pensions At A Glance 2015 report said.

Retirement ages have risen substantially, with retirement at 67 becoming the new 65 in many countries, the report said. Several countries are planning to move towards 70, including the Czech Republic, Denmark, Ireland, Italy and the UK.

"Most governments have made important efforts to bring public pension systems on a sustainable path; while these are steps in the right direction, there is now a growing risk in some countries that future pension will not be sufficient," OECD secretary-general Angel Gurria said.

"The long-term challenge is to design policies today that are flexible enough to adapt to the uncertainties of tomorrow's world of work, while ensuring adequate living standards for retirees."