Trump last month asked Justice Juan Merchan to block their testimony, arguing Cohen had a history of lying and would likely lie again, and that Daniels - whose real name is Stephanie Clifford - would seek to use the trial to monetize her story.
In rejecting Trump's request to block Cohen's testimony, Merchan wrote he was unaware of any basis for Trump's "rationale that a prosecution witness should be kept off the witness stand because his credibility has been called into question."
The Republican presidential candidate has pleaded not guilty to 34 counts of falsifying business records to cover up his reimbursement of Cohen for the payment to Daniels for her silence about a sexual encounter she says she had with Trump in 2006. Trump denies an encounter.
A trial had initially been scheduled for March 25, but last week was delayed until at least mid-April due to a last-minute dispute over evidence disclosure. Merchan is expected to decide on a new trial date after a March 25 court hearing.
A spokesperson for Manhattan District Attorney Alvin Bragg, whose office charged Trump last year, declined to comment. Trump's lawyers also declined to comment.
He has also pleaded not guilty in the other cases, which focus on his efforts to reverse his 2020 loss to Biden and his handling of government documents after leaving office in 2021.
In the Manhattan case, prosecutors argue the Daniels payoff was part of a broader "catch-and-kill" scheme Trump and Cohen hatched to buy the silence of people with negative information about the candidate. Cohen pleaded guilty to violating federal campaign finance laws in 2018.
Merchan on Monday also denied Trump's request to exclude testimony from or any evidence about the three people who received hush money payments. These included Daniels, a doorman and Karen McDougal, a former Playboy model who says she had an affair with Trump, which he also denies.
"The evidence and testimony surrounding these individuals is inextricably intertwined with the narrative of events and is necessary background for the jury," Merchan wrote.
Prosecutors argued the October 2016 payment to Daniels was made as the Trump campaign panicked about his standing with female voters, following the leak of an "Access Hollywood" tape in which Trump boasted about forcing himself on women.
In a modest victory for Trump, Merchan said prosecutors could ask witnesses about the tape, but agreed with Trump that playing the clip itself for the jury could cause him "undue prejudice." The judge said he may reconsider that ruling "should the Defense open the door."
