The Swedish parliament is set to vote on new legislation that will require companies to increase the number of female board members they have, Reuters reports.

A gender quota of at least 40% women forlisted firms by 2019 has been proposed by Prime Minister Stefan Lofven and the country's minority centre-left coalition.

Morgan Johansson, Sweden's justice minister, revealed in 2014 that the law would be drafted if companies did not reach the quota of their own accord by the time of their 2016 board meetings. He promised a “substantial penalty” awaits firms that fail to meet the new law.

The proportion of female board members has improved somewhat over the past decade, standing at 32% last year.

Four of Sweden's most prominent businesswomen have also hit out at the plans. 

Writing last summer in the Dagens Nyheter newspaper , they rejected legislation where “we are separated by gender and other factors we cannot influence.” 

“As soon as we introduce quotas in one area it will become more difficult in principle to prevent it elsewhere,” they said.

The neighbouring nation of Norway became the first country in the world to impose such a gender quota in 2003. It ensured that at least two out of every five board members for over 500 firms were women.

France, Germany and the Netherlands have similar proposals in the works.