LOS ANGELES (CBSLA) — President Trump and the Republican Party are suing California over its new law that requires candidates to release their tax returns in order to appear on California’s primary ballot.

The new law requiring all presidential and gubernatorial candidates to release their tax returns was signed by Gov. Gavin Newsom last week.

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The lawsuit claims California’s law is unconstitutional because it creates an additional requirement to run for president. It also claims the law would deny voters an opportunity to vote for their chosen candidates.

Presidential candidates have traditionally released their tax returns, but President Trump is the first in decades to buck the tradition. Trump says he cannot release his tax returns because they are under audit.

The president has called the new California law “more of the record-setting presidential harassment.”

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The conservative group Judicial Watch also sued Monday over the new law.