The RNLI has accused the Daily Mail newspaper of publishing a "very unfair, one-sided portrayal" of the charity, claiming that it is being run by left-wingers on large salaries.
An article published by the newspaper on Saturday under the headline "Mayday! Britain's heroic lifeboat volunteers are drowning in a sea of political correctness imposed by highly-paid pen pushers" did not include a response from the RNLI.
The article, which has been shared by 4,500 people, highlighted recent dismissals of volunteers as examples of political correctness at the RNLI.
The dismissal of two lifeboat volunteers in Whitby, North Yorkshire for superimposing a crew member's face on a naked model's body on mugs features prominently in the piece.
It also highlighted disputes with crews in places including St Helier, Scarborough, Arbroath, Anglesey and Merseyside.
"To have mass resignations at one lifeboat station might be considered unfortunate, but to suffer at least seven such cases in a period of around 18 months is somewhat more worrying." the article says.
"One possible explanation to the situation is, ironically, that the RNLI has become too popular for its own good – at least when it comes to fundraising."
The article said 35 senior executives earned more than £60,000 in 2016.
It quoted an anonymous fundraiser saying departments were being run by "third sector careerists with no knowledge of the sea, or what makes lifeboats tick, who try to import left-wing values".
Comments posted at the end of the online article includes one that says: "I'll never donate to these vile, greedy people again."
An RNLI spokesman told Third Sector three members of staff spoke to the Daily Mail before the article was published.
The spokesman said: "They spent 90 minutes on the phone to the journalist answering questions open and honestly and correcting any factually incorrect information, providing up-to-date figures where they were using old figures. Plus, we sent a written statement as a follow-up on Friday."
You may have read the RNLI story in today's Daily Mail. Despite providing a statement & interviews with 3 RNLI people, inc volunteers, they've included none of this. This is our response to a very unfair one-sided portrayal of our charity & all those who dedicate their time to it pic.twitter.com/QGk4lxdsiI— RNLI (@RNLI) May 12, 2018
He said the organisation was "proudly apolitical".
Regarding claims the RNLI was cash-rich, he said the value of the charity's assets fell by about £43m in 2016 and its investments reduced by about £3m.
The RNLI tweeted to its 130,000 followers on Saturday: "Despite providing a statement and interviews with three RNLI people, including volunteers, they've included none of this.
It was hard core graphic pornography that newspapers would not print Anji. The mock up images reported in the newspapers are nothing like those involved in this issue.— RNLI (@RNLI) May 13, 2018
"This is our response to a very unfair, one-sided portrayal of our charity and all those who dedicate their time to it."
A link takes followers to the 500-word statement on the RNLI website.
The statement said the organisation "must adhere to the very highest standards of safety and behave in a way that meets the expectations of a modern emergency responder"..
It said it did not "stand volunteers down lightly", but the examples in the article "involved serious incidents that we were duty bound to challenge".
It added: "We simply will not tolerate lifeboats being taken for joyrides in rough weather without full crew
"We don’t accept that hard-core, graphic pornography has any place at a lifeboat station.
"We will not tolerate threats of violence towards our volunteers or staff. We will not stand for bullying or aggressive behaviour."
Recent disputes, the RNLI said, involved less than 1 per cent of its 6,000 operational volunteers.
"We cannot operate in the same way we did 30 or 40 years ago, when the world was a very different place."