Don Groves is a Deadline contributor based in Sydney

The heads of most major Australian media companies have written an open letter to the government warning that its proposed media reforms will lead to a massive increase in regulation, stymie free speech and jeopardize billions of dollars’ worth of media assets. They say a  mooted public interest test could be misused by politicians to block the acquisition of media companies by people they don’t like or agree with. This is widely seen as a reference to mining tycoon Gina Rinehart, the largest shareholder in Fairfax Media, who is demanding three seats on the board. The board has refused, citing Mrs Rinehart’s unwillingness to sign the company’s charter of editorial independence. Many Fairfax journos fear Rinehart, who owns nearly 19% of Fairfax, would use her influence to pursue her agenda against the government’s carbon tax and the tax on mining profits. The Communications Minister, Senator Stephen Conroy, said last week he will soon present to the cabinet plans to regulate the media and impose on owners a public interest test. That could allow a new independent regulator to veto media deals if they curbed editorial independence, free expression of opinion or fair and accurate presentation of news. The letter was signed by the heads of News Ltd,  Foxtel, AAP, APN, Seven West Media, Nine Network and the Australian News Channel. Fairfax was not a signatory as a spokesman explained the company didn’t think the letter had the “right tone.’ The federal Opposition has vowed to repeal any such reforms if it wins power at the next election due to be held before November 2013.