Carmena, a former Communist judge who became mayor of Madrid after May's local elections, was vilified by right-wing newspaper La Razón when it broke the story on its front page this week of her choosing to take a "luxurious" holiday.
The newspaper reported how Carmena was missing Madrid's La Paloma fiesta in favour of holidaying in the "exclusive resort" of Atlanterra in Cádiz, southern Spain, where she is staying in a €4000-a-week villa with her family.
The article described the Villa Isbilia in great depth, highlighting that it cost €3,900 per week to rent and was located on "one of the most exclusive" stretches of the Costa de la Luz. The article was accompanied by a photograph of the 71-year-old mayor in her swimsuit at the beach.
Its scathing criticism was joined by that of the ruling Popular Party, who slammed Carmena's "double standards".
"The mayor can spend her money how she likes but in a time of economic crisis when many people in Madrid are not able to go on holiday, public officials need to set an example in their conduct," said Fernando Martínez Vidal, councillor for the Popular Party's Municipal Group in Madrid.
It seemed to be the perfect opportunity for her rivals to show that the mayor had indeed succumbed to the trappings of office, abandoned her communist roots and was living it up in the lap of luxury.
The truth however, was far less sensational.
Carmena, who did away with mayoral privileges on taking office, was quick to respond on Twitter, saying it was a shame La Razón had run the article without first verifying the facts with her.
"About my holiday, I would have liked a serious publication like La Razón to have asked: there are 8 people sharing the rent and bills of the house."
De las vacaciones, me habría gustado que un periódico serio como La Razón preguntase: 8 personas en la casa compartiendo descanso y gastos.— Manuela Carmena (@ManuelaCarmena) August 18, 2015
Taking that into account, Carmena's "luxury holiday" actually cost her €650, when you divide the cost of the villa by the six adults staying there, along with two children.
Madrid city hall sources confirmed that Carmena had travelled down to Cádiz in her daughter's car and was returning by train, therefore not spending any public funds on her summer vacation.
Many Spaniards have sprung to Carmena's defence via social media, arguing that she can spend her money how she likes and countering that the Popular Party could not talk after the amount of scandals to hit it in recent years.
Ahora Madrid, the left-wing coalition with which Carmena ran for office, tweeted ironically:
"We understand that for La Razón the scandal is that Manuela Carmena has paid for her own holidays and not had them paid for by some lobby group."
Entendemos que para La Razón el escándalo es que @ManuelaCarmena se pague las vacaciones de su bolsillo sin que la invite ningún lobby.— Ahora Madrid (@AhoraMadrid) August 18, 2015
A spoof account for former President of Madrid and vocal critic of Carmena, Esperanza Aguirre tweeted sarcastically: "It's a scandal that Carmena has paid for her own holiday and hasn't used her official car to make her daily visit to the hairdre…"
Es un escándalo que Carmena se pague sus propias vacaciones y no use el coche oficial para ir diariamente a la pelu… pic.twitter.com/sLDXp9sRT6— Esppeonza (@EsppeonzAguirre) August 18, 2015
Another tweeter compared Carmena's trip to that of Ana Mato whose family trip to disneyland when she was an MP was reportedly paid for by the state.
- ¡Carmena se gasta 4.000€ de su bolsillo! - ¡Ana Mato fue a Disneyland con dinero público! - ¿Y? ¡La progre es Carmena! Y así...— Guille Ibernón (@guilleibernon) August 18, 2015
Twitter user David Ramos Pascual wrote: "I don't care if Manuela Carmena shares the costs or not, people can spend their own money however they like."
A mi me da igual si @ManuelaCarmena comparte gastos o no, es tan sencillo como que cada uno gaste su dinero en lo que le dé la gana— David Ramos Pascual (@dramospas) August 18, 2015