Cable&Wireless is expected to announce major job cuts on Tuesday as the telco refocuses on large companies rather than smaller firms.
John Pluthero has already warned staff that 485 positions have been earmarked for the axe.
"That's just the start," Pluthero said in a memo sent to C&W staff. "As we reduce the number of customers we serve, fix some of our problems, strip out layers of management, we will need fewer people to run the business... If you are worried that it all sounds very hard, it's time for you to step off the bus. This is no longer a place for the timid."
Pluthero was damning about the state of the UK telecoms market in general, and gave C&W's own performance a slating.
"Congratulations, we work for an underperforming business in a crappy industry and it's going to be hell for the next 12 months," he wrote.
The telecoms market has suffered in recent years from debts and overcapacity created in the boom times of the late 1990s. C&W, which must compete in the UK with a dominant BT, has suffered from low prices. Its decision to buy Bulldog has also been questioned after the ISP suffered widespread problems getting new customers connected.
Earlier this month, C&W issued a profits warning and announced the departure of chief executive Francesco Caio.
C&W wouldn't reveal the full details of Tuesday's announcement, but said that it would "outline our strategy going forward for the next couple of years".
The memo appeared in the Sunday Times, which reported that Pluthero is planning to change C&W's focus so it concentrates on large customers whose telecoms bills can run into tens of millions of pounds.
Pluthero wrote that he wants to see C&W "selling less stuff but making better profits out of it", comparing this to being Giorgio Armani rather than Top Shop.
C&W has been losing jobs since last August when it bought rival telco Energis, where Pluthero had been serving as chief executive.