The Lib Dem leader was joined by his wife on the campaign trail
Liberal Democrat leader Nick Clegg has unveiled details of his party's policies affecting families.
Pledges include greater flexibility for working parents, respite for carers of the elderly and an "ambition" of free care for 18 months to five-year-olds.
The party also plans to bring 250,000 empty homes back into use by offering grants or cheap loans for renovation.
The Conservatives had earlier outlined plans to offer tax breaks to some married couples.
Mr Clegg was joined by his wife - in her first appearance on the campaign trail - as he tried some dry-stone walling at a farm in his Sheffield Hallam constituency, ahead of the policy document launch.
It repeats their pledge to allow people to earn £10,000 before paying income tax - paid for by a tax on properties worth more than £2m.
It says they would extend the right to request flexible working to all employees and giving fathers and grandparents more chance to take time off to look after children.
In a foreword to the document, Mr Clegg said: "Liberal Democrats will give all mothers and fathers the support and flexibility they need to spend time with their children.
"Following the birth of a child, we will allow parents to share leave between them.
"We will cut taxes for all working families on low and middle incomes, not just a select few."
Other policies include ensuring every nursery is led by a graduate, and childcare workers having an NVQ level 3 or higher qualification. Their other childcare pledge would extend the current arrangements, allowing 20 hours free a week.
The policy on respite care - applying to people who care for loved-ones for more than 50 hours per week - would be funded by scrapping Labour's commitment to free care at home.
The party says its other policies will be funded by scrapping schemes such as ID cards, the next generation of biometric passports and cutting back burdensome regulation of local authorities.