The ABC is imposing a new round of cuts at Radio National with eight staff and several programs to be slashed from the 2017 schedule.

Sources told Guardian Australia all but one of RN’s music programs will be cancelled as the network becomes a talk-only station.

RN Afternoons, The Body Sphere, Soundproof, Daily Planet and The Live Set are expected to be cancelled along with the religious affairs program Sunday Nights with John Cleary.

Conservative commentator Tom Switzer, an adjunct fellow of the Institute of Public Affairs, has been given another show in addition to Between the Lines.

Switzer will replace Jonathan Green as the host on Sunday Extra, which is RN’s live Sunday morning broadcast of Ockham’s Razor, Background Briefing and First Dog on the Moon.

First Dog’s Sunday morning slot Guide to Modern Living has also been dropped, the cartoonist for Guardian Australia has revealed. He said in a post on Facebook he didn’t mind being axed but he was unhappy Switzer was taking over the program.

“To be honest I don’t mind too much – we were talking about needing to refresh the format anyway (getting canned is very refreshing!) however I am annoyed that the IPA are taking over the whole Sunday morning.

“Anyway, thanks to everyone who has listened to the worst 4 minutes of radio in Australia over the journey it has been extremely fun and you are all very nice.”

The changes are expected to save at least $3m which will be spent on ABC Radio’s digital strategy.

The ABC’s decision to end the 15-year-old Sunday Nights has raised the ire of religious leaders who met with Guthrie last week to protest.

The redundancies come just weeks after the managing director, Michelle Guthrie, told a Senate estimates committee there would be no redundancies at RN.

Asked last month by Greens senator Richard di Natale if there were planned cuts or redundancies at Radio National, Guthrie said: “I can tell you that we are not planning any redundancies on any particular programs at the moment but I will try to reiterate to you that the programming strategy is not static, nor has it ever been, and we will regularly review our program schedules across radio, across television and across our news output.”

A spokeswoman confirmed ABC Radio would announce the 2017 schedule this week.

“As with every annual commissioning process, there are some changes planned across all networks,” the spokeswoman said. “These changes are aimed at serving our audiences better and attracting broader audiences with engaging, appealing content. No final decisions about positions have been made at this stage, just as they had not been made at the last session of the Senate estimates committee.”

Guardian Australia understands staff will be told of the changes this week and some will be moving to new shows, while others will be leaving the network.

The upheaval will be a bruising start for Judith Whelan, a former editor of the Sydney Morning Herald, who took up her new role as the head of spoken content at ABC Radio only last week.

The changes won’t be the last. By 2020 RN is likely to be transformed from a broadcast network into a digital platform.

“In 2017, RN will embody digital content creation from the beginning, through to the end, with all our content,” a confidential briefing document said.

“This will coexist with a high regard for our linear audience. An increased investment in digital will help us reach younger and more diverse Australian audiences.”

Staff were angered by an earlier warning from the ABC Radio director, Michael Mason, who told them they had to accept change because “a defensive mindset and a belief that the ABC will flourish regardless of the industry and competition will not work”.