An engineering firm in northern Italy has sparked controversy after making almost half its workforce redundant – and selecting only women.

A union official quoted the company as having reported to the small businesses association: "We are firing the women so they can stay at home and look after the children. In any case, what they bring in is a second income."

No one at the company, Ma-Vib, which is based in Inzago near Milan, could be reached for comment.

With Italy's prime minister, Silvio Berlusconi, on trial for paying an underage prostitute, there is a continuing and lively debate over the status of Italian women, which some international surveys suggest is abnormally low in comparison with the rest of Europe. In February, there were demonstrations in more than 250 cities around the world in defence of the dignity of Italy's women.

"In this country, at the government and company level, there is always the same old thinking – that it is preferable that women stay at home", said Maria Sciancati, general secretary of the FIOM engineering union.

There was condemnation too from the equal opportunities councillor in Milan's conservative-led administration. Cristina Stancari, who once worked in Berlusconi's press office, said the firm's action showed "discrimination and an utter lack of respect for women – a return to the past that cannot in any way be justified".

Ma-Vib, a family-owned company, makes electric fans and blowers for air conditioning, refrigeration and heating equipment. According to the FIOM, it employed 12 men and 18 women before the redundancies. Faced with a downturn in sales, the firm decided to get rid of 13 of the women.

The FIOM called a strike to protest at the move. But, in a development that raised further criticism, only one of the men whose jobs had been saved heeded the strike call.

The women who have lost their jobs are all aged between 30 and 40. They were employed in the assembly of Ma-Vib's products.

Italy has one of the EU's lowest female employment rates, partly because of pressure on women to give up their jobs when they become pregnant. One in five does not return to work after the birth of her first child.