President Donald Trump has denied receiving a subpoena from Special Counsel Robert Mueller after a former federal prosecutor made the case the president may already be fighting a quiet battle to resist a demand for grand jury testimony.

'No,' Trump responded Wednesday when DailyMail.com asked him if he had been subpoenaed at all by Mueller, as the president addressed reporters at the White House before leaving for a Florida campaign rally.

Trump lawyer Jay Sekulow also denied a subpoena existed, after Politico published an essay from former federal prosecutor Nelson Cunningham arguing that telltale signs may indicate the beginnings of a court fight over the issue.

'The report in Politico is completely false,' Sekulow told DailyMail.com. 'There has been no subpoena issued and there is no litigation.'

Cunningham was previously a prosecutor in the Southern District of New York under Rudy Giuliani, who is also a member of the president's legal team.

IT'LL BE GRAND: A former federal prosecutor is making the case that President Trump may already have a received a grand jury subpoena and his lawyers are likely fighting it in a sealed legal battle

In his essay, Cunningham weaves together a scenario based upon what is and is not known about a secret case making it through a high-level appeals court.

'Since mid-August, [Mueller] may have been locked in proceedings with Trump and his lawyers over a grand jury subpoena,' Cunningham wrote in Politico Wednesday.

Docket entries reveal that a secret grand jury case was opened August 16th.

Just a day earlier, Giuliani had said Trump's team was 'pretty much finished with our memorandum opposing a subpoena.'

A judge issued a ruling on on Sept. 19, and the losing party promptly appealed the matter to the D.C. Circuit Court of Appeals, the powerful court that would handle inter branch disputes.

A Politico reporter overheard a conversation in the clerk's office that indicated Special Counsel Robert Mueller's office was involved, according to the account.

A man requested a copy of the most recent filing from the special counsel in order to produce a response, but declined to identify himself when he was approached.

Just hours later, the D.C. Circuit received a sealed response in the legal dispute.

Arguments are set for Dec. 14th in the case surrounding the unknown person who is fighting the subpoena.

The shrouded legal battle comes as Mueller's team has generally laid low in the final weeks before the elections, as expected given Justice Department guidelines meant to discourage actions which could have a political flavor.

A reporter overheard a man requesting a file relating to Special Counsel Robert Mueller just hours before a filing in a sealed dispute was presented to the court

Trump lawyer Rudy Giuliani spoke of a memorandum opposing a subpoena

Nevertheless, Mueller's office issued a statement Tuesday announcing it had forwarded a matter to the FBI regarding an alleged attempt to smear Mueller with a fabricated claim of sexual harassment.

Nelson W. Cunningham

On Oct. 19 it was revealed that theJustice Department has charged a Russian woman with a conspiracy to 'sow division and discord' in the U.S. elections – including the upcoming midterms.

Trump has at times said he was eager to talk to Mueller's team, however his lawyers have fought a prolonged battle to prevent him from facing questioning. The sides have haggled over those questions could be conducted in writing, and what their scope would be – Russian election interference or also inquiries into alleged obstruction of justice.

There are other clues that point to a vigorous battle over the witness – who may or may not be the president.

Giuliani has long telegraphed that Trump would fight a subpoena

When the Circuit Court ruled against the witness, the person's attorneys immediately sought an en banc appeal – one that could go before the entire D.C. Court of Appeals.

Of note is that Judge Gregory Katsas – who was appointed by Trump – recused himself from the matter.

Judges often recuse if they have a personal or professional issue with a party in the case. Katsas, having worked in the White House counsel's office and been appointed by Trump, might well have had to recuse, notes Cunningham.

If the witness were Trump, 'then Judge Katsas would certainly feel obliged to recuse himself from any official role,' Cunningham writes.

There is also the matter of the dispatch the court has shown to move the matter quickly through the process – a potential sign of its urgent importance.

After an Oct. 10 ruling, the parties filed a motion to have it handled in an expedited fashion. Judges granted the motion in just two days. The witness got only 11 days to file briefs on the matter, and the other party (in this scenario, potentially the special counsel) got only two weeks to respond. There is another deadline Nov. 14, and oral arguments are set for a month later, Dec. 14th.

'At every level, this matter has commanded the immediate and close attention of the judges involved – suggesting that no ordinary witness and no ordinary issue is involved,' writes Cunningham.

Giuliani has long argued that Trump would fight a subpoena.

'If Mueller tries to subpoena us, we're going to court,' the president's lawyer told ABC News in June.

Trump's legal team also argued in writing that the president couldn't obstruct justice because this would amount to 'obstructing himself.'

'It remains our position that the President's actions here, by virtue of his position as the chief law enforcement officer, could neither constitutionally nor legally constitute obstruction because that would amount to him obstructing himself, and that he could if he wished, terminate the inquiry, or even exercise his power to pardon if he so desired,' his lawyers argued in a letter obtained by the New York Times this summer.