WASHINGTON (Reuters) – Democratic presidential candidates will hold the first of six primary debates on October 13 in Nevada, the party said on Thursday, setting out a debate calendar that rivals of frontrunner Hillary Clinton say is insufficient.

Announcing the calendar on the day of the first Republican primary debate, the Democratic National Committee set the five other Democratic contests in Iowa, New Hampshire, South Carolina, Florida and Wisconsin. The first debate in Nevada will be hosted by CNN.

Clinton’s opponents have complained that six debates are not enough to allow them to shine against the former secretary of state who has dominated media coverage so far in the Democratic race.

Clinton leads opinion polls of the five people who have announced they are running for the Democratic nomination at the November 2016 election. Vermont Senator Bernie Sanders is her nearest challenger.

Another rival, former Maryland Governor Martin O’Malley, complained that the debate process would restrict candidates’ voices.

“What they’re proposing does not give you, the voters, ample opportunity to hear from the Democratic candidates for president,” he said in a statement.

DNC Chair Rep. Debbie Wasserman Schultz said the debates “will highlight the clear contrast between the values of the Democratic Party which is focused on strengthening the middle class versus Republicans who want to pursue out of touch and out of date policies.”

Later on Thursday, real estate mogul Donald Trump will be at center stage in Cleveland, Ohio as 10 leading Republican presidential candidates look for a break-out moment in their first debate.

(Reporting by Alistair Bell; Editing by Andrew Hay)

Photo: Hillary Clinton answers a reporter’s question in front of a sign reading “Pant Suit Power” following a town hall campaign stop in Nashua, New Hampshire July 28, 2015. REUTERS/Brian Snyder)