Mumford & Sons and Sir Elton John have called on fans to help them fight the "battle" against ticket touts.

Mumford and Sons

Mumford and Sons

The 'I Will Wait' hitmakers and the 68-year-old legend have blasted the practice - also known as secondary ticketing - which sees people buy up tickets for an event to resell them at a profit, and an open letter on the group's website has addressed music-goers directly asking them to join them.

The letter reads: "Many tickets on secondary sites are being sold by touts who are simply in the business of ripping off the fan by charging an extortionate amount for sold out shows ... We need your help to win this battle."

"Yes, there are some fans legitimately trying to sell on tickets to other fans because they can't make a show for whatever reason - but we believe this is a tiny percentage of the business being conducted on secondary tickets sites. We strongly urge you to use a platform like Twickets, ScarletMist and other face-value-only sites if you can't make a show and need to sell on your tickets."

And while the band - which includes Marcus Mumford, Winston Marshall, Ben Lovett and Ted Dwane - recently visited the British parliament to offer their support for an investigation into Secondary Ticketing they insist they have exhausted a number of means to combat the practice over the years.

The letter continues: "Behind the scenes over the years, we have tried a lot of different ways to beat the touts including trying to get as many of the tickets as possible for a show to sell ourselves through ticket companies that we choose; we hold back tickets to put back on sale at face value nearer to the show so that fans have a second bite of the cherry at buying tickets at the right price."

Meanwhile, Sir Elton called the practice - which also takes place outside of music venues - "disgraceful" and urged fans to stay at home rather than pay an unfair charge for a gig.

Speaking to the BBC on Wednesday (16.12.15), he said: "I think it's extortionate and I think it's disgraceful. The fact that they're willing to pay that [amount] is fantastic, but I just think I'd rather they save their money and not come."