Telstra has been accused of a cover-up after it refused to provide details on numbers of network faults, citing commercial confidentiality.
Labor's regional services spokeswoman Sue Mackay asked Telstra to provide a breakdown of outstanding network faults after evidence to the Senate showed there were more than 3500 in Tasmania alone.
Initially, Telstra agreed to provide details but later refused to put them on the public record claiming 'commercial-in-confidence' reasons.
"It is clear Telstra has something to hide, otherwise it would not have claimed the database that holds all of these faults would be commercial-in-confidence," Mackay said.
Telstra estimated there were between 10,000 and 20,000 network faults outstanding at any one time, 18 per cent of them high priority.
The company said it would allow Senate members to look at the details as long as the information remained private.
Telstra's refusal to disclose faults coincides with its plans to cut 250 jobs from its Network Design and Construction (NDC) unit after chopping 400 positions last year.
Figures released in the Senate show 61 of the 188 redundancies offered by the end of March were to regional employees: 50 in NSW, nine in Queensland and two in Tasmania.
The location of another 62 job cuts was still to be decided.