"With these changes, which we have been discussing with employer organisations and trade unions, the additional expenditure from this range of changes is close to fifty million euros," the minister said, adding that he expected that "a little over fifteen thousand pensioners" would take advantage of the new rules.

He stressed that the generation of workers who are able to benefit from them is characterised by particularly long contributions careers, as a result of having worked when they were still children.

The new rules approved at Thursday's cabinet meeting will make it possible from 1 October for anyone to retire who is aged at least 60 and who has been contributing for at least 48 years, or for at least 46 years if they began working at no more than 14. Contributions may have been made to the general social security system or to the special pension system for public sector employers, or to a combination of the two.

"These are people who started to work very early, to whom society owes a debt, and whom it can now give a benefit through access to a full pension without penalty" for retiring before the official age.

The retirement age in Portugal is currently 66 and two months, having been steadily increased in recent years to take account of rising life expectancy, and is to increase by a further month from January 2017.

Not everyone was happy with the new rules, however. A spokesman for the Left Bloc - one of the parties that provides the minority Socialist government with its support base in parliament, said in an interview with Lusa on Thursday that this change to pension rules "took more time than it should have" and that it fell short of what was desirable, even after having been amended under pressure from the other parties.