While some players such as Maro Itoje, Alun Wyn Jones, Stuart Hogg and Tadhg Furlong are expected to be included in the touring party, generally there is serious competition for places across the squad.
However, as is always the case, form will also play a crucial part in the selection process, with established players coming under pressure from those who might not generally be seen as contenders.
Here are five such players, whose form in this season’s Six Nations has seen them move into contention for a place in the Lions squad.
1. Hamish Watson (Scotland)
Openside flanker is so competitive for the summer – Sam Underhill, Justin Tipuric, Peter O’Mahony, Josh van der Flier and Tom Curry all in the running – but based on opening three rounds then Watson is the man.
DID YOU KNOW? At the start of his English professional career he moved to Oakham in Rutland and was at the Leicester Tigers Academy