An ambitious plan to improve mobile phone coverage in rural Britain has been emphatically rejected by network operators, sending the government back to the drawing board.

Ministers had proposed a new "national roaming" scheme that would let customers use any mobile phone network for voice calls in areas with no reception. Similar agreements exist wen roaming overseas, where networks have deals to let customers use rival networks.

Ed Vaizey, the digital economy minister, wrote to mobile executives asking for their support to strike a deal by the start of 2015. But all the UK networks immediately rejected the plans as unworkable and undesirable.

"It was rejected. There are reasons why it wouldn't work from a technical and legal perspective," a source told the Financial Times .

Culture secretary Sajid Javid originally proposed the plans, with prime minister David Cameron also complaining about poor mobile reception in rural areas. With the original plans were rejected out of hand, Ed Vaizey has now asked mobile networks to come up with different ideas to improve voice coverage in the UK.

The government could even invest public money into the scheme in a bid to tackle so-called "not spots" before the general election. Another proposal put forward would see mobile networks share basic infrastructure, but there are concerns that such a move would damage competition.

Mobile phone networks spend millions on installing new masts to boast the best coverage and sharing such technology could damage comeptition. No other country currently uses "national roaming" with experts pointing to technical problems with specifically sharing voice traffic across all networks.