Singtel Optus chief executive Allen Lew has told staff "they will be sacked" if they are found to be upsetting customers and has encouraged employees to "dob in" colleagues who are not up to scratch, after the telco had a 35 per cent surge in complaints.

The telecommunications company holds weekly “TGIF” (Thank God It’s Friday) meetings, where Mr Lew speaks to hundreds of Optus’ staff in person at the business’ Macquarie Park campus in Sydney and live-streams the conference to Brisbane, Melbourne and Perth. At the last two TGIFs a furious Mr Lew warned employees of his no-nonsense approach to improving their reputation with Australians.

Optus CEO Allen Lew has blasted staff over the company's surge in complaints. Credit:Edwina Pickles

“The customer is why we exist. If you make customers unhappy, you will be sacked," Mr Lew told employees, according to a staff member at the meeting.

Two weeks ago, the Telecommunications Industry Ombudsman released data showing a jump in complaints from Optus customers, with 40,665 issues brought to the ombudsman’s attention in the last financial year. This included the period covering the telco’s World Cup fiasco, where customers trying to stream struggled to view the matches, ultimately leading Optus to share its exclusive rights with public broadcaster SBS.