“There is no basis for continuing to rush,” Blanche wrote.
Blanche sent the letter to Merchan on Wednesday after the judge rejected the defence’s latest request that he step aside from the case.
By adjourning the sentencing until after that election, “the Court would reduce, even if not eliminate, issues regarding the integrity of any future proceedings”, Blanche wrote.
Merchan, who has said he is confident in his ability to remain fair and impartial, did not immediately rule on the delay request.
A message seeking comment was left with the Manhattan district attorney’s office, which prosecuted Trump’s case.
Trump was convicted in May of falsifying his business’ records to conceal a 2016 deal to pay off porn actor Stormy Daniels to stay quiet about her alleged 2006 sexual encounter with him.
Prosecutors cast the payout as part of a Trump-driven effort to keep voters from hearing salacious stories about him during his first campaign.
Trump says all the stories were false, the business records were not and the case was a political manoeuvre meant to damage his current campaign. Manhattan District Attorney Alvin Bragg is a Democrat.
Trump’s defence argued that the payments were indeed for legal work and so were correctly categorised.
Falsifying business records is punishable by up to four years behind bars. Other potential sentences include probation, a fine or a conditional discharge which would require Trump to stay out of trouble to avoid additional punishment. Trump is the first ex-president convicted of a crime.
Trump has pledged to appeal, but that cannot happen until he is sentenced.
In a previous letter, Merchan set September 18 for “the imposition of sentence or other proceedings as appropriate”.
Blanche argued in his letter seeking a delay that the quick turnaround from the scheduled immunity ruling on September 16 to sentencing two days later is unfair to Trump.
To prepare for sentencing, Blanche argued, prosecutors will be submitting their punishment recommendation while Merchan is still weighing whether to dismiss the case on immunity grounds.
If Merchan rules against Trump on the dismissal request, he will need “adequate time to assess and pursue state and federal appellate options”, Blanche said.
The Supreme Court’s immunity decision reins in prosecutions of ex-presidents for official acts and restricts prosecutors in pointing to official acts as evidence that a president’s unofficial actions were illegal.
Trump’s lawyers argue that in light of the ruling, jurors in the hush money case should not have heard such evidence as former White House staffers describing how the then-president reacted to news coverage of the Daniels deal.