Mobiles complicate getting a line on voters Some of the most influential political pollsters are ignoring millions of voters because they only call landlines. Even so analysts are unsure whether that will affect the accuracy of the polling, despite one-in-five Australians being mobile phone-only users. The number of people who only use mobiles grew 20 per cent to 24 million in the past year, with most users city-dwelling renters aged under 35. The Australian Communications and Media Authority said there were now only 10.4 million landlines registered. Landline response rates are almost certainly declining. A professor of politics at Macquarie University, Murray Goot, said that while pollsters have been battling with the problem of changing technology for some time, there is no evidence that the mobile-only surge has affected the accuracy of the election polls. "Landline response rates are almost certainly declining," he said. As mobile phone use increases, pollsters will be increasingly concerned that they're getting it right. But he said pollsters who don't call mobiles - Nielsen and Newspoll - ensure the spread of ages and gender match those in the census. Professor Goot said he was unsure if mobile-only users would vote differently to those using landlines. "I think mobiles gradually will be called more, but it's a question of how good the mobile databases are," he said. The operations manager at polling company ReachTel, James Stewart, said acquiring mobile phone data lists could be expensive, and they needed accurate address information in order to target seats. ReachTel, which polls using a mix of mobiles and landlines, started contacting mobiles for polling purposes in 2011. But Nielsen polling director John Stirton said landline-only phone polls, conducted by trained interviewers, still continued to provide "consistent and reliable results."