Boston Mayor Michelle Wu is kicking off her campaign for re-election with a strong lead over her opponent Josh Kraft, according to an Emerson College poll released Thursday.

Michelle Wu holds a double-digit lead over philanthropist Josh Kraft in the race for Boston mayor, a new poll from Emerson College finds. The preliminary election to narrow the field down to two candidates is in September.

The survey offers the first early look at the matchup between the first-term progressive mayor and her most prominent challenger.

Boston mayoral candidate Josh Kraft says public records show the city’s bid process for the White Stadium pro soccer rehab project was “rigged” and is calling for an investigation into whether Mayor Michelle Wu violated procurement laws.

Boston Mayor Michelle Wu leads billionaire philanthropist Josh Kraft in the first poll of the city’s young mayoral campaign, but a decent share of voters remain up for grabs. Forty-three percent of respondents to the new Emerson College poll say they support the Democratic incumbent,