Speaking at an ACAS and the Department of Business Innovation and Skills (BIS) briefing in London yesterday, Swinson said more businesses must start to "change traditional working cultures".
"I believe [flexible working and shared parental leave] will be economically beneficial to employers," Swinson said. "With these measures workers are more likely to be happy in work, you'll see reduced sickness absence, improvement in mental health issues and will result in more motivated and healthy workers."
Swinson added: "We need to change working cultures to reflect a modern workforce. We are still stuck in the 1950s – all these old stereotypes are a thing of the past."
Also speaking at the event was Anne Sharp chief executive of ACAS, who echoed Swinson's thoughts. "Flexible working is about modernising the workforce," she said.
Sharp said these proposals present "great opportunities" for business to get the best out of their workforce and will give them the "ability to recruit and retain the most talented employees".
She said: "It used to be seen as a perk and for years companies used to say 'it will work there but not in my company', but we've seen it can work."
"Offering flexible working can also help plug the large skills gap we have in the UK."
The changes are scheduled to come into force in 2014 for the extended right to request flexible working and 2015 for shared parental leave.
Any employee who has been with the company for 26 weeks or more will have the right to request flexible working and an employer will have to consider every request.