Shadow communications minister Malcolm Turnbull says the ABC will take on a crucial role as a source of well-funded, independent news as the nation’s biggest newspapers continue their demise.

Mr Turnbull, who worked briefly as a journalist in England while studying at Oxford University in the late 1970s, praised ABC managing director Mark Scott and said that a Coalition government would provide strong backing for the public broadcaster.

The pledge of support comes as billionaire mining magnate Gina Rinehart prepares to seize control of the board of Fairfax Media, in what is widely regarded as an attempt to steer its mastheads towards a more conservative line. That would leave the ABC as the only major liberal voice in the daily Australian media.

The opposition leader, Tony Abbott, has congratulated Mrs Rinehart for investing in Fairfax at a time when traditional media is in precipitous decline.

Mr Turnbull said he rejected the proposition that Coalition governments were less favourably disposed towards the ABC. “The ABC has enjoyed strong support under the Coalition. The other public broadcaster, SBS, was actually founded by a Coalition government, so I just don’t buy that at all.

"We don’t have any plans to do anything other than support the ABC. If there’s an Abbott government, I’ll be the communications minister and I’ll be responsible for the ABC. I think the ABC has to be run efficiently and taxpayers have to get value for money. It’s got to be absolutely scrupulous in its objectivity and balance.

"But I have to say that I think Mark Scott does a very good job. He’s got to keep doing a very good job, but he has been a very effective chief executive and he is highly regarded.”

A recent Essential Media Poll found that ABC TV and radio were among the most trusted media organs in the country. The esteem in which they are held is likely to be consolidated by the inexorable decline of the newspaper business and the erosion of quality in the content newspapers provide.

“The ABC is considered more trustworthy than politicians,” Mr Turnbull said. “It’s important that it continues to be trusted.”

On Monday Fairfax Media said it would cut 1,900 jobs over the next three years. The company will move The Sydney Morning Herald and The Age to tabloid format and erect paywalls around its news websites in preparation for a digital-only future. News Ltd followed with an announcement yesterday that it would also embark on a major restructure of its news business, in a two-year overhaul that is expected to cost at least 1,000 jobs across the country.

The developments have been accompanied by much public discussion over the expected decline of quality journalism, and the threat that would pose to the standard of public debate and policy.

“The role of the ABC is crucial now,” Mr Turnbull said. “The fact of the matter is that the great foundations of journalism have been the newspapers, historically. They’ve employed the most reporters, they’ve done the most reporting, and they have set the agenda in terms of the bulk of the news coverage.

"What’s happening is that their business model is being dramatically undermined by the internet, and the drift of advertising dollars away to other digital platforms. And so the viability, indeed the survivability, of many newspapers is very questionable. And if they do survive as digital publications, they’re unlikely ever again to have the reporting depth in terms of the journalistic resources that they had in their heyday as printed.

"So the ABC by default is becoming more and more important. The role of the public broadcaster becomes more important - having a source of news and information that is well-funded is really crucial, and so the ABC becomes more important than ever.”