T-Mobile and Sprint headed to court on Monday to defend a merger some consider too big.
The telecom companies will try to convince a judge that the state attorneys general suing to stop T-Mobile from buying Sprint - are wrong.
Attorneys for 13 states and the District of Columbia will argue in Manhattan federal court that combining the number 3 and 4 wireless carriers would drive up phone bills, especially for those with pre-paid plans.
While the companies argue that a bigger T-Mobile - which would result from a $26 billion deal - would be better suited to innovate and compete to push down prices.
The battle to merge started in 2014 during the Obama administration but officials at the Justice Department and Federal Communications Commission urged the companies to drop the idea, which they did.
Fast forward to 2019 - the Trump administration signed off on the planned merger after the companies agreed to sell Boost Mobile - owned by Sprint - to Dish.
If the deal is approved, the merger would leave just three nationwide wireless carriers: Verizon, AT&T and the new T-Mobile.