MEPs are to vote next month on pioneering legislation that will secure mandatory paternity leave for heterosexual fathers and the partners of gay mothers for the first time.

If successful, the new law will ensure that all 27 EU member states will adopt measures to give new fathers and partners of new mothers two weeks’ compulsory paid leave, meaning that paternity leave in the UK will no longer be voluntary.

Labour MEP Mary Honeyball was one minister present on the women’s rights committee who amended the European Commission proposals on parental rights to reflect the changing dynamics of family life.

Ms Honeyball told PinkNews.co.uk: “Co-maternity is a relatively new concept. It’s very important that we recognise that LGB couples have children and that this is respected and enshrined in law.”

Voting on the matter will begin during the first week of May and Ms Honeyball warns that it could be a “lengthy process” and that there will be “very interesting arguments on both sides of the debate”.

Lord Mandelson will represent the UK at the EU council of employment ministers where the proposals have to be agreed upon by a majority.

The proposals have met opposition by some Christian Democrat and Conservative MPs, including UK Conservative employment spokesman Philip Bushill-Matthews MEP who voiced his concern by saying: “The EU should not be dictating to any British mothers and fathers how much leave they must take.”

In the UK, maternity leave is granted to any mother who has given birth to a child.

As the law currently stands, paternity rights apply if the father is the biological father of the child or if the father or is fully involved in bringing up the child.

Men whose partners are the biological fathers of a child cannot currently take paternity leave, even if they will bring the child up together.

However, male partners who adopt a child together are given full adoption leave.

Two weeks of paid leave must be taken during the first 56 days of the child’s life.

Paternity rights can be available for fathers and ‘second mothers’ who have adopted a child, but this needs to be considered alongside provisions on adoption rights so that one person cannot claim both paternity and adoption leave.