AT&T is targeting T-Mobile US with a special offer that offers up to $450 for subscribers to switch networks, following an aggressive campaign by its smaller rival in 2013 led by colourful CEO John Legere.

In typical style, Legere did not hold back in a statement following AT&T’s announcement of its new offer, which he characterised as “a desperate move” by the larger player.

“We used AT&T’s cash to build a far superior network and added un-carrier moves to take tons of their customers – and now they want to bribe them back!” he said.

T-Mobile is set to make its own tariff announcement at CES 2014 on 8 January, which will further pump up rivalry between the two rivals.

The smaller rival claimed its so-called un-carrier approach is showing traction among users.  This approach involves simplified tariff plans with no annual contract, and enabling customers to upgrade their devices twice a year for a fee (rather than locking them into two-year contracts). It has also scrapped data roaming for 2G services.

AT&T’s new offer is time-limited and includes a bill credit of $200 and up to $250 for a handset trade-in, depending on the model’s value.

“This is a desperate move by AT&T on the heels of what must have been a terrible Q4 and holiday for them. I’m flattered that we have made them so uncomfortable!” added Legere’s statement.