Men dominate the list of newly selected Labour parliamentary candidates in the party's target winnable seats for the 2015 election, wherever the selection has been kept open to men and women.

Since the last election, an astonishing 17 of the 18 nominations in open contests for target seats have been won by men, figures given to the party's national executive show.

Overall, this trend has been countered by Labour's continued use of all-women shortlists in many constituencies. Since the election, all-women shortlists have been drawn up in 22 target seats. So, of the total of 40 target seats where candidates have been chosen so far, 23 have gone to women – but only thanks to the use of positive discrimination.

It may be argued that constituencies that refused to run all-women shortlists were aware of the number of such lists in other seats and therefore felt free to select men – or that the most impressive women candidates were on the all-female lists. Either way, Labour has selected a man in almost every constituency where an all-women list has been blocked.

With the election little more than two years away, the parties are rapidly getting their candidates in place. The Liberal Democrats are deciding how many candidates they will need, based on a strategy to campaign largely on their local record, meaning incumbency will be key.

Labour is the only party to use all-women shortlists to counteract the apparent continuing prejudice in politics in favour of selecting men. It had been hoped that their use over the past decade would lead to a natural willingness by constituency parties to select women in open contests, but if anything the tide is running in the opposite direction.

The Labour List website points out that in 13 byelection selections (which are always open to both sexes), only four of the candidates have been women. Since May 2010, only three women – Lucy Powell, Seema Malhotra and Debbie Abrahams – have beaten male candidates in open selections. Coventry councillor Lynnette Kelly was selected for Warwick and Leamington, but she defeated another female candidate.

Labour is aiming for half its selections to be from all-women lists. In most regions the party's national executive has already decided which constituency selections should be open and which should be closed to men. The national executive is trying to do this on a regional basis, but has to take into account that Labour is more likely to win seats in some regions than others.

In total, the NEC has agreed recommendations for 108 targeted parliamentary constituencies, with 52 all-women shortlists.

A separate process is under way for Labour-held seats in which the sitting Labour MP is standing down.

In the current parliament, 31% of Labour MPs are women – a considerably better representation than the other parties (the Tories have 16% and the Lib Dems 12.5%). However, as a result of losing seats in the 2010 election, the total number of women Labour MPs fell from 98 to 81.

The Conservatives created a priority list of candidates known as the A list of whom 50% were women, leading to a doubling of Tory MPs to 48, short of its target of 60.

The use of all-women lists has been controversial in the Labour party; in the 2005 election the Labour candidate in Blaenau Gwent was defeated and the local party accused headquarters of not listening, in choosing from an all-women list.

David Cutts and Paul Widdop in the British Journal of Politics and International Research have reported there was no negative reaction from the electorate in the 2010 election when a candidate was selected from an all-women shortlist, even after taking into account incumbency status.

In 1996, Labour was found by an industrial tribunal to be in breach of the 1975 Sex Discrimination Act and was forced to cease the selection of candidates based on all-women lists. The law was subsequently changed.

A Labour spokesman said the shortlists were the only way to guarantee women made progress in politics, and added that less than 30% of Tory candidates were women.