The European Commission has stopped short of imposing legally-binding quotas to bolster the number of women on company boards.
Commission Vice President Viviane Reding wants a target set instead to have women comprise at least 40% of the boards of publicly-traded European companies by 2020.
State-owned companies will have an earlier deadline of 2018 under the plan, which is yet to be fully endorsed and is subject to alteration.
The current proposals would demand that from 2016, companies where women make up less than 40% would have to choose qualified women to fill vacancies or face penalties, but it would be up to individual EU countries what penalties there would be for failure.
Ms Reding faced a storm of protest over plans to write the 40% target into law - with some women's groups arguing the best person for the job should get the post.
While agreeing women are under-represented, they suggested positive disrimination to correct the imbalance risked alienating male counterparts.
Fiona Hotston Moore, a corporate partner at the accountants Reeves, told Sky News that "unconscious bias" was the biggest obstacle to the problem as self-regulation had failed.
She called for temporary quotas to help improve the imbalance.
But in giving his response to the European Commission's directive, the Business Secretary, Vince Cable made it clear that self-regulation was to continue.
He said: "The UK welcomes the Commission's decision not to impose mandatory quotas for women on boards.
"We remain fully committed to increasing women's representation in UK boardrooms but along with like-minded Member States, we have consistently argued that measures are best considered at national level.
"We believe that the UK's business-led, self-regulatory model, as set out in the Davies Review, is the best approach for us."