3 has long called for an end to high ‘mobile termination rates', which can account for as much as 80% of the price per minute of a call from a home phone line to a mobile.
But the mobile company, along with BT and other partners, is now trying to bring the campaign to light among consumers.
Mobile termination rates are charges paid by operators to connect calls to mobiles and are at the root of the high cost of calling mobiles. They account for 4.7 pence, or more, of every minute of a call to a mobile.
Last year UK mobile operators made £750m from fixed-line customers calling mobiles.
The group is asking consumers and businesses to register their support for a fairer deal at www.terminatetherate.org.
The European Commission has recommended that national regulators like Ofcom take a new approach to bring costs down to reasonable levels.
The Terminate the Rate Campaign has been joined by Moneysupermarket.com, the Federation of Small Businesses, Carers UK, the GMB Union and NUS.