Seeking to defuse tensions, the Democratic National Committee said Friday it will hold public hearings around the country to develop the platform for its summer convention, a focal point for supporters of presidential candidate Bernie Sanders.

DNC Chairwoman Debbie Wasserman Schultz, a Florida congresswoman, announced that a 15-member platform drafting committee will hold hearings in Washington on June 8-9, Phoenix on June 17-18, St. Louis on June 24-25 and Orlando, Florida, on July 8-9, about two weeks before the Philadelphia convention.

The party will also allow rank-and-file Democrats to submit written or video testimony or request to testify in person by going online at https://demconvention.com .

Heading into California's June 7 primary, Sanders has vowed to amass as many delegates as possible at the convention to try to win the nomination against front-runner Hillary Clinton. Clinton holds a substantial lead among delegates and has been calling for unity as she closes in on the nomination in the final stretch of the primary calendar.

But the platform could provoke a fight between supporters of Clinton and Sanders who are tangling over the party's future.

Sanders' campaign has accused Wasserman Schultz of providing more favorable conditions to Clinton during the primaries, pointing to the quantity and timing of debates and a dispute over access to party data.

He objected to some of the appointments to the committee that will consider the platform, a statement of the party's values adopted at the convention every four years, saying it was unfairly tilted to benefit the former secretary of state. But most of the seats on the 187-member Platform Committee were made by the campaigns according to vote tallies.

Separately, the DNC recently named the 15-member panel to put together the first draft of the platform, including some Sanders' allies like Rep. Keith Ellison of Minnesota and Dr. Cornel West.

Wasserman Schultz has denied that she placed her thumb on the scales for Clinton during the primaries. In a statement, she said the platform is "an expression of Democrats' values and our process will ensure they have their voices heard."

The Vermont senator wants the party to include in the platform strong statements about undercutting wealth inequality, the influence of Wall Street and campaign finance reform. He has also vowed to make the party more open and welcoming of working-class voters and independents.

The platform drafting committee will be chaired by Rep. Elijah Cummings, a Maryland Democrat who has endorsed Clinton, and include other supporters of Clinton and Sanders as well as neutral members. Cummings said in a statement that the hearings are aimed at "broadening the process to welcome and include input from across the nation."

"I want to ensure we take up the issues at the center of people's lives so I hope Democrats will make time to share their perspectives," he said.