Berlin -- German Chancellor Angela Merkel, Forbes magazine's most powerful woman in the world for the fourth year running, called on women Monday to fight for their right to equal pay.

Germany's first female leader said in an interview with feminist magazine Emma ahead of a general election next month that the pay gap between the sexes was a "real problem".

"I advise any woman who earns less than her male colleague for the same work to go to her boss self-confidently and say something has to change!" she said.

The 55-year-old premier of Europe's top economic power said ahead of the September 27 poll, however, that she did not favour state regulation to level the playing field.

"But we politicians will keep up the pressure," she pledged.

Merkel's comments drew an attack from her post-election coalition partner of choice, the liberal opposition Free Democrats (FDP), who said the chancellor herself bore her share of the blame for skewed pay between the sexes.

"Several studies show that there is hardly another European country where so few mothers work than Germany," the FDP's Bavarian chapter chief Sabine Leutheusser-Schnarrenberger, told the daily Tagesspiegel.

Leutheusser-Schnarrenberger, a former German justice minister, said the difficulty many women have balancing work and family capped their career prospects and salaries.

"The government has failed to strike a new balance in its family policy initiatives. With substantially better childcare and full-day schools, women would have better chances of finding well-paid jobs."

Merkel aims to ditch her current coalition partners, the Social Democrats, in favour of the FDP. Polls show they are likely to win a ruling majority.

On average, women in Germany earn 23 percent less than men, compared to an average of 17 percent in the rest of Europe, a study by the Düsseldorf-based Institute of Economic and Social Research found.

It attributed the gap to factors including a tax system that encourages women to take a part-time job when their husband earns more than they do, as well as a scarcity of creche places and early school closing hours.

In the same interview, the childless Merkel divulged her own secrets for juggling work and her personal life, telling Emma that despite the demands of her job, she and her husband, chemist Joachim Sauer, shared out the domestic chores with the help of a housekeeper.

"We talk about who will turn on which washing machine when, who will hang out the laundry to dry," she said. "Or who will do the shopping."

She said her publicity-shy husband did not cook.

"I write him a list and then he does the shopping for the weekend," she said.

AFP/Expatica