Josh Kraft, son of the billionaire New England Patriots owner and head of the family’s philanthropic arm, is planning to announce a run for mayor of Boston, according to two sources close to Kraft. The challenge would set up a showdown with first-term Mayor Michelle Wu for this year’s election.

Kraft spent much of last year meeting with potential supporters, testing the waters for a run. Apparently, he has decided that there is enough discontent with Wu to make an opponent viable.