Every new father in Britain is to be given a "dads' guide" that will include an explanation of breast­feeding and tips on how to support their partner.

The move will be announced in a government green paper on families and relationships this week, which is expected to be focused on the role of men and will lay out government plans to encourage stable relationships.

Ministers are trying to counter suggestions that policies for parents have been too focused on mothers. They are also trying to match Conservative attempts to make the family a central policy issue, with commentators describing this year's poll as the "Mumsnet election".

The green paper will argue that involving fathers more in their ­offspring's early years is not only good for the child, but can also help the couple's relationship.

The guide will be placed inside the Bounty Pack, a package of information and advice about pregnancy and the early months of a baby's life that is given to all new mothers. It has been put together by the Fatherhood Institute (FI), which is also ­producing ­a manual for midwives so that they can offer fathers more support.

Rob Williams, chief executive of FI, said providing fathers with more information during pregnancy and birth would help them become much more involved in their child's first few months. "All communications go to the mother, even if the father is in the same room," he said. "Fathers tell us that they get the impression they are not important. Yet if they understand breastfeeding and support it, mothers are much more likely to be successful when doing it."

Williams said there was evidence that when fathers had a one-hour session on breastfeeding before the birth, the mother was twice as likely to be still doing it after six months.

"There is also a lot of evidence that children do better in school if fathers are involved in their education," he added. "And work shows that, where fathers are more involved with childcare, the couple are more satisfied in their own relationships. Sharing duties seems to make a marriage more stable."

Teachers will also be asked to engage more with fathers, including sending them school reports if a pupil's parents have separated.