The band were speaking ahead of the launch of their second album Babel, set to be released on Monday (September 24).
The Sun reports that drummer and accordion player Ben Lovett was defensive about the criticism they have received from 'folk purists', saying: "The cynics can just all f**k off."
He continued: "We think this new record will attract a different audience which is really exciting. And broaden people's view of us."
Guitarist Ted Dwayne added: "We have made so many sacrifices and we've not taken the easiest route... and so I hope people do understand where we are coming from because it's a good place, not a capitalistic venture at all."
Banjo player Winston Marshall also argued; "Basically it's been four mates having the best three years of their lives, and that's simply going to continue."
Mumford and Sons will play the Roundhouse in London on September 24 as part of the iTunes festival.
Watch the video for their single 'I Will Wait' below: