Saga, the insurance and travel company for the over-50s, has apologised after customers were sent a brochure advertising a cruise “exclusively for Brits”.

Twitter user Anthony Bale, who is a university professor, said his mother was “outraged” after being sent the magazine, outlining the characteristics of the cruise.

He posted a photograph of the promotion, which read: “Exclusively for Brits. Exclusively adults only. Exclusively for over-50s.”

Outraged phonecall from my mother: she was shocked to receive @SagaUK brochure advertising cruises “exclusively for Brits.” She asked me why they would say this & if it’s legal. 🤷🏽‍♂️



(Also, in terms of grammar pedantry, “Exclusively Adult Only” + “For Over 50’s” is distressing) pic.twitter.com/3giXg5iybD — Anthony Bale (@RealMandeville) September 19, 2019

Shortly after Bale posted a photograph of the brochure, the “Over 50s lifestyle” section of the Saga website went offline, followed by the entire website, reappearing later during the morning. It is unclear whether the website fault was related to the promotion.

Saga subsequently apologised, insisting that people of all nationalities were welcome on its tours and cruises.

“We are extremely sorry for the error in the promotional leaflet that was sent to the database of one of our cruise partners,” said a spokesperson.

“Whilst inside the leaflet it mentions our cruises depart from UK ports only, the wording that was intended to highlight this key benefit on the front cover was interpreted incorrectly and was wholly inaccurate.

“Saga Cruises have a proud heritage of welcoming anybody over the age of 50, of any nationality, onboard our cruises. The error has been corrected with immediate effect and we would like to apologise for any offence this may have caused.”

It said cruise.co.uk had drafted the wording but admitted that Saga had signed off on it.

Bale’s mother, Ruth Bale, 75, a retired probation officer, told the Guardian she was shocked to receive the brochure. “I think it’s a very sad reflection that it’s seen as a marketing point, that you’d want to go on a cruise exclusively composed of one nationality.

This is not a Saga brochure. Our partners at https://t.co/cMByEGL4cj are extremely sorry for any offence the inaccuracy in their leaflet may have caused. Saga cruises all depart from the UK but we welcome anybody, of any nationality, over the age of 50 on our cruises. — Saga (@SagaUK) September 19, 2019

Chris Gardner, chief executive of cruise.co.uk, owned by private equity group Bridgepoint Development Capital, also apologised for the “error”.

“The wording is not a reflection of what we intended. It’s a mistake that I need to get to the bottom of and who allowed those words, which I can understand are offensive.

“All we can do is apologise for any offence that was caused, it doesn’t reflect our company.”

While Saga came in for criticism over the content of its marketing material, shares in the company surged by more than 15% on Thursday, as profits fell by less than expected.

Profits were cut in half to £53m for the six months to the end of July but the company insisted that an overhaul of its insurance business was bearing fruit.

But it warned that Brexit has hurt its travel insurance business and made consumers reluctant to commit to holidays in 2020/2021 after earlier anticipating an impact only this year.