Battleborn will require a persistent internet connection to play, 2K has confirmed, regardless of whether you're playing through the game's single-player campaign or co-operatively with friends.
In a statement provided to VideoGamer.com this morning, 2K explained: "Battleborn requires an internet connection to play, whether you're playing singleplayer, co-operatively with friends, or competitively against others. One of the reasons for this is that experience points earned in Battleborn's Story Mode carry over to Multiplayer and vice-versa.
"All XP earned through the game's persistent progression system contributes to leveling up individual Character Rank, as well as player profile Command Rank. In addition, maintaining data integrity is a major priority for the team, and online gameplay permits player's data to be accessible, even after experiencing a hardware malfunction or purchasing a new console."
A PlayStation Plus account will also be required to access "certain gameplay and functionality", the game's PS4 box art states, with the same presumably true for the Xbox One version.
Earlier today, 2K confirmed that Battleborn's open beta will arrive on PS4 on April 8, five days earlier than Xbox One and PC. The full game, meanwhile, is due to roll out on May 3.
Source: 2K Games