Now it’s the turn of the largest US operator to be on the receiving end of some outspoken words from its smaller rival, and its idiosyncratic CEO.

T-Mobile US has unveiled a new marketing campaign called Never Settle Trial that mocks Verizon Wireless’ advertising campaign of the same name.

The trial enables Verizon Wireless subscribers to come over to its rival for a limited-period, free trial.

“Last week, I said we would hit right back at Verizon – I meant it,” said John Legere, CEO of T-Mobile US.

Legere followed with bullish comments that its 4G network can match rivals.

“T-Mobile’s 4G LTE network is the nation’s fastest. Not faster for the price … just faster, period. With T-Mobile, you don’t have to settle for trickery, gimmicks and carrier BS the way you do with Verizon,” he said, in customary manner.

“I’m so confident in our kick-ass network experience that we’re footing the bill so Verizon customers can give T-Mobile a try,” added Legere.

T-Mobile US has previously scorned rivals AT&T and Sprint but largely steered clear of Verizon Wireless.

With the Never Settle Trial, Verizon subscribers can port their numbers to a new T-Mobile US smartphone but hang onto their old phone just in case the move does not work out.

After the trial, if they are happy with the new service then T-Mobile will pay off any early termination fees levied by Verizon (up to $650) or any outstanding device payments.

Alternatively, subscribers who are not happy after the change can just hand in their new T-Mobile phone within 14 days and will get a refund for any trial costs incurred, or any service costs from Verizon.

Never Settle Trial starts on 13 May, and Verizon subscribers can sign up until 31 May.