Britain’s gender pay gap is worse than any other country in Europe and costs the country up to £23bn each year, a government-appointment commission has revealed.

Findings from the Women and Work Commission (WWC), a report commissioned two years ago by Tony Blair, have shown that women working in full-time positions are earning 13% less than their male counterparts.

The report shows an even wider gap at 41% between men and women at the part-time working level, with women earning an average of 59p for every £1 received by men.

Overall, the economy suffers a loss of £23bn in lost productivity and talent, according to the WWC’s analysis of official figures.

The economy could recoup this loss by removing certain barriers to women working in occupations traditionally done by men and by providing more incentives for women’s participation in the labour market, the WWC said.

The report blames, in particular, a reluctance by bosses to allow staff to jobshare or reduce their hours, which is forcing many women with children and other caring responsibilities to take part-time jobs that do not utilise their talents.

The WWC also found a high number of cases of women who had been sacked during maternity leave or missed out on pay rises upon their return.

Among its 40 recommendations, the WWC suggests more government support for training schemes, such as targeted training for women returning to work after having a baby and a campaign to inform schoolgirls of their potential career prospects and pay rates.

Trade unions, however, said the report does not go as far as it should have in its proposals, criticising the WWC for failing to call for mandatory equal pay audits.

“The time for measuring the pay gap is over. Now is the time to close it,” said Diana Holland, national organiser for women, race and equalities at the Transport & General Workers Union (T&G).

“We are disappointed that it has fallen short of recommending mandatory pay audits and legal rights for equality reps. Audits simply ensure an employer is complying with the law. Without an audit, employers will be vulnerable to thousands of individual, costly equal pay cases.”

Brendan Barber, general secretary of the Trades Union Congress (TUC), added: “Of course we are disappointed that the Commission could not agree on mandatory pay audits in the private sector, but that should not obscure the positive policies that now go forward with strong endorsement by this broadly based Commission.”