RTÉ staff will ballot this week on entering formal negotiations with management as relations deteriorate over the station's refusal to reinstate previous wage cuts. A series of meetings will be held before the vote is taken, and a key issue will be the "disproportionate" salaries of star broadcasters such as Pat Kenny, Ryan Tubridy and Marian Finucane.

The Trade Union Group (TUG) was due to meet with management last week but moved to seek a mandate from its members to do so.

A countrywide ballot will begin on Tuesday with the result expected by 1 February. However, even if the TUG was denied permission to meet with management, RTÉ sources said industrial action was unlikely.

"The opening position is likely to be that the time period [for a temporary pay cut which expired on 31 December] is up, so where is our money?" a source said. "RTÉ said it can't pay it. Staff said there was no other agreement. It is quite clear that management are looking for negotiations – not to tell staff what their position is."

As well as ballots in Dublin, it is likely union officials will travel to the regional centre in Cork, Lyric FM in Limerick, Raidió na Gaeltachta in Galway and to TG4, where some Nuacht employees are based.

"I would be very surprised if there was a vote for any kind of industrial action," a source said.

If staff reject formal talks with management, unions would then have to examine their options. It is believed, however, that next week's vote will sanction talks.

The stand-off follows a recent meeting in which an external review of the station's financial health found that the reinstatement of staff pay cuts will almost certainly not happen, based on budget forecasts that predict a big deficit for 2011. However, while staff are said to be reconciled to the idea of an extension to pay cuts, the issue of "disproportionate" wages for the highest-earning stars will feature prominently in any negotiations.