obstinate

(as) obstinate as a mule

Extremely reluctant or unwilling to change a particular opinion, behavior, or course of action, especially when faced with opposition. My toddler is as obstinate as a mule, and he'll throw a tantrum any time he doesn't get what he wants. You'll never get Rich to change his opinion—he's obstinate as a mule.
See also: mule, obstinate
Farlex Dictionary of Idioms.

*stubborn as a mule

 and *obstinate as a mule
Cliché very stubborn. (*Also: as ~.) I tried to convince Jake to go to the doctor, but he's as stubborn as a mule. For four years, Henry pestered his parents to let him learn the trumpet. They tried to talk him into some other, quieter instrument, but he was stubborn as a mule, and now he has a trumpet.
See also: mule, stubborn
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

stubborn as a mule

Extremely obstinate, as in He's stubborn as a mule about wearing a suit and tie. This simile evokes the proverbial stubbornness of mules, whose use as draft animals was once so common that the reputation for obstinacy can hardly be as warranted as the term indicates. [Early 1800s]
See also: mule, stubborn
The American Heritage® Dictionary of Idioms by Christine Ammer.

stubborn as a mule

If someone is as stubborn as a mule, they are determined to do what they want and very unwilling to change their mind. For all his pleasant manner, the Texan was stubborn as a mule, and he didn't like being pushed. Old Greg is also stubborn as a mule. He won't say anything — he'll just carry on doing what he planned. Note: This expression is usually used to show disapproval.
See also: mule, stubborn
Collins COBUILD Idioms Dictionary, 3rd ed.

stubborn as a mule

extremely stubborn. informal
See also: mule, stubborn
Farlex Partner Idioms Dictionary

(as) ˌstubborn as a ˈmule

(often disapproving) very determined not to change your opinion or attitude; obstinate: If you tell her what to do, she won’t do it because she’s as stubborn as a mule. Why not just suggest it to her?
See also: mule, stubborn
Farlex Partner Idioms Dictionary

stubborn as a mule

Singularly obstinate. No one knows why mules in particular have been singled out for this quality, but they have, for centuries. “Contrary” and “obstinate” are other adjectives used in the simile, which became current in the early 1800s and remains so. The same is meant by the adjective mulish.
See also: mule, stubborn
The Dictionary of Clichés by Christine Ammer
See also:
  • (as) obstinate as a mule
  • (as) stubborn as a mule
  • mule
  • stubborn
  • stubborn as a mule
  • be (as) stubborn as a mule
  • cooperate on (something) with (someone or something)
  • cooperate with (someone or something) on (something)
  • cooperate with
  • cooperate with (someone or something)
References in periodicals archive
A proper filter F of L is said to be n-fold obstinate if for all x, y [member of] L, x, y [not member of] F implies [x.sup.n] [right arrow] y [member of] F and [y.sup.n] [right arrow] x [member of] F.
Folding theory applied to residuated lattices
This matter must wait for another book, though, which will concern Pound, the 'Nineties, and the great fictionalisers, Tennyson, Swinburne, Rossetti, who lie behind them." The book she alludes to, "Obstinate Isles" (1973-75), exists only as an outline and small group of draft chapters.
Introduction
Perhaps with obstinate rigor we can restore what we've lost.
'Progress' in psychiatry
wondering , why some parties demande the expulsion of Iranian ambassador due to vague speculation but obstinate to demande expulsion of Kuwait or Turkey Ambassador, he said.
MP for SIIC calls on the Government of Kurdistan to provide evidence confirms Iranian attack
She added: "Although it is fair to consider that management of an influx of migrants should be the responsibility of the European Union, the request for revision of the Schengen agreement along the lines suggested by the two heads of state is evidence of either total ignorance of European legislation or, more certainly, of their obstinate refusal to work out European solutions, or even to invalidate them".
MEPS DENOUNCE FRANCO-ITALIAN SUMMIT
The attendants expressed their support for President initiatives calling for a national dialogue andrejected the obstinate positions of the opposition parties which
President meets sheikhs, dignitaries of Arhab, Nehm districts in Sana'a
"We have tried all venues to get in touch with Omar, but he remains obstinate. He does not want to speak with any of us and we do not even know what the reason of his action is," Ahmad Al Kamali, the UAEAA President, told Gulf News.
Athletics association bans gold medallist sprinter Al Sulfa
How often have we suffered the frustration of taking a carving knife or hand saw to obstinate and excessively packaged goods?
Attack packaging; emails & letters
Timid Democrats, obstinate Republicans, a risk-averse White House and a sour public outlook that green groups couldn't counter.
United States : Climate change plan collapses in Senate
David Forster, policy and strategy director at Yorkshire Ambulance Service, said the health service employed "too many who are lazy, unproductive, obstinate, militant, aggressive at every turn".
'Lazy' NHS staff storm
Summary: England have scraped a 17-12 victory over an obstinate Italy to maintain their winning start to the Six Nations.
England labour to victory over Italy
An obstinate Toronto Chief of Police, Bill Blair, claims he is going by the rulebook.
Shop owners beware
What good can such missions achieve with Israeli leaders becoming more obstinate? Ayyoub asked.
Mideast-Peace
Indeed, some formerly obstinate lenders are now loosening their restrictions so developers can reduce prices below previously agreed-upon minimums, known as "release prices."
Developers going back to the bank
Are you the strip of light glancing the wall, the obstinate refusal to quit or give in?
Anna Kuerner