Ryanair chief executive Michael O’Leary has refused to apologise to a rape crisis centre which criticised him for describing rival airlines as “high-fare rapists”.

Speaking to journalists, O’Leary said some people were “desperate to get to Ryanair’s low fares because they can’t afford to fly with the high-fare rapists around Europe”.

O’Leary doubled-down on his choice of words when asked about them at the time, and later refused to apologise when the Dublin Rape Crisis Centre (DRCC) wrote to him asking for apology, in a letter seen by the BBC.

Ireland’s deputy premier Simon Harris said it was “clearly an inappropriate use of language” and that O’Leary “should have moved to rectify it”.

Transport Secretary Heidi Alexander told UK radio outlet LBC that victims of rape are “not going to be rushing to book tickets with him, let’s be honest”.

O’Leary made the comments on Thursday while talking to journalists ahead of Ryanair’s yearly meeting with shareholders.

Asked by a reporter from the Press Association whether the language was appropriate, he said: “Absolutely.”

“British Airways, Lufthansa, and everybody else’s high fares, I’ll happily offend them on a regular basis,” he added.

Asked whether it would offend sexual assault victims, he said rape was “a terrible crime”.

Following O’Leary’s comments, the DRCC’s chief executive Rachel Morrogh wrote to O’Leary accusing him of trying to get a headline with his comments.

She said the DRCC had received calls from rape victims who were “upset and distressed because of what you said”.

She offered O’Leary training on the impact of sexual violence and urged him to apologise.

“I can’t imagine you would ever use the term so flippantly again if you truly understood [what] it was like to survive rape,” she wrote.

In response, O’Leary said: “I am quite clear that no remarks of mine could possibly trivialise the heinous crime of rape.”

He added that as he had not “trivialised the heinous crime of rape” he would “not be issuing any apology or accepting your offer of training”.

It is not the first time O’Leary has offended people while talking about his business.

In 2004, he reportedly called the owners of Stansted Airport “a bunch of overcharging rapists”, external in a row over airport charges.

He has also previously called some of his own staff “lazy bastards” and once said to passengers looking for a refund “we don’t want to hear your sob stories”.

In June, he said the airline would “reluctantly” stop charging parents to sit next to children after a watchdog investigation was opened, but insisted its previous policy complied with laws.