Greece toughened its legislation on Thursday to define rape as any non-consensual sexual act, following criticism that an earlier proposed overhaul of the current definition was too lenient to offenders.

The last-minute change approved in parliament was lauded by activists who say it lessens the burden of proof for alleged victims.

Current legislation defines rape as a forced sexual act following violence or the threat of "severe or direct danger," and punishes offenders with a minimum five years in prison.

The change is part of a broader criminal law reform that reduces sentences for some serious offenses but ensures that more convicted criminals get sent to prison.

After the law comes into effect on July 1, people convicted of rape will serve five to 10 years in prison.

The Amnesty International rights group hailed the new definition as a "historic victory" for women in Greece.

"This newly amended law finally recognizes the simple truth that sex without consent is rape and makes it clear that physical violence is not required for the crime to be considered rape," said Eirini Gaitanou, an Amnesty activist in Greece.

Gaitanou added that Greece is only the ninth country in Europe to pass such a law.

In other tweaks to the overall legal reform package, the government watered down plans to drastically reduce sentences for people found guilty of running a criminal organization or of making, possessing or supplying petrol bombs.

This last provision had angered opposition parties who said it would encourage use of Molotov cocktails — which anarchist and far-left demonstrators often use against the police.

The law approved Thursday also stipulates that all sentences of more than three years in prison must be served. Under the current system, in many cases offenders can buy off their sentences or secure release on appeal.