Peter Lewis, the commercial television executive who wrote the blueprint for cuts to the ABC, has been installed by the Abbott government to the public broadcaster’s board for a five-year term.

Communications minister Malcolm Turnbull announced the appointment on Thursday, the day after the ABC board met to consider savings measures, including those suggested by Lewis in his efficiency review.

“He will be a valuable addition to the ABC board, bringing with him extensive and deep industry knowledge and experience,” Turnbull said.

Lewis was selected by a nomination panel which included two newly appointed members: the conservative commentator Janet Albrechtsen and the former Liberal politician Neil Brown.

Lewis’ addition to the ABC board comes at a crucial time for the future of the broadcaster which is currently deciding which programs and services will be cut as well as designing a major restructure of the organisation.

At risk is news and current affairs programming on radio and TV, including the local versions of 7:30 and Lateline.

On Thursday Turnbull refused again to outline when or by how much the ABC’s $1.1bn budget would be cut.

“Look, we are making cuts to the ABC and SBS budget, that is true,” he said on ABC Radio’s AM program. “And we are – my focus has been, ever since the election, to ensure that the savings made by the ABC and SBS are focused on removing back-office costs, excessive back-office costs and waste, and are not simply cancelling programs, cutting programs and reducing the resources available to programming.”

Before the election last year Tony Abbott promised: “No cuts to education, no cuts to health, no change to pensions, no change to the GST and no cuts to the ABC or SBS.”

But in the May budget the Coalition slashed $43.5m over four years out of the ABC and the SBS budgets and is now demanding more.

The appointment was branded hostile and politically motivated by Community and Public Sector Union president Michael Tull. “The board has a statutory obligation to uphold the ABC charter and to be independent of the government,” Tull told Guardian Australia.

“This appointment has the potential to undermine that independence. This is because the government is appointing the person who has just completed a controversial and secret review of the ABC that the board is currently considering, and the government is trying, via threatened budget cuts, to force the ABC to adopt its recommendations.”

The Abbott government appointed the two ABC critics to the nominations panel in July.

Albrechtsen, a columnist for the Australian, has called for ABC managing director Mark Scott to resign and Brown has called for the ABC to be privatised.

On Thursday Brown was quoted in the Australian saying he didn’t watch Lateline anymore and he didn’t think it was “the really wonderful program now that they are saying it is”.

The former chief financial officer at Seven West Media was commissioned by Turnbull earlier this year to find so-called backroom savings at the ABC and the SBS but his report has never been released publicly.

Lewis has worked at the Sydney Olympic Broadcasting Organisation and Network Ten as well as Seven and held numerous board positions including Australian News Channel Pty Ltd, TXA Australia Pty Ltd and Yahoo 7 Australia.