Luxury Cruise Line Cunard has decided to relax its dress code rules which has set off complaints from passengers.

Cunard is changing its evening-wear options from "formal", "semi-forma", and "elegant casual" to simply 'formal' and 'informal'. They will also have only three formal nights a week on Transatlantic cruises and two during Mediterranean and Scandinavian voyages, the Daily Mail reports.

It is not yet clear what "informal" will mean for the ship, but some see this as Cunard lowering their standards.

Many cruise fans took to Cruise Critic to express their disappointment over the decision.

"We left behind a long period of expensive 'loyalty' on another cruiseline when it dumbed down its dress codes so much, it felt like we were paying all that money to eat in somewhere like a Mcdonalds outlet...can't call them restaurants," user Lucky White Feather said, according to the Daily Mail.

"Because we save up hard to take cruise holidays as we consider them to be a "something special" holiday. We look forward to the chance to 'dress up' while we are enjoying dinner/show/dancing every night etc...something we never have an opportunity to do at home."

Many are wondering where else they might go is Cunard becomes a more casual cruise line.

"I understand how you feel. But where are you going to look? As far as I can tell, Cunard is the most formal line out there," user 3rdGenCunarder said.

Some aren't bothered by the change and said they would still wear a tie and jacket.

For their four or five "informal" nights, Cunard said jackets are still required but ties are optional.

"The glamour of dressing to the nines is a hallmark of travelling with Cunard, and distinguishes us from the mass of cruise operators where dressing up has become a thing of the past," Peter Shanks, Cunard's president and managing director said according to the Daily Mail.

"In a world where everything seems to tend towards the casual, Cunard is proud to give passengers the opportunity to put on their best bib and tucker and bring an extra special sense of occasion to an evening at sea.

"On other nights, we aim to loosen the tie - making it optional - but we will still require men to wear a jacket."

Those who don't want to dress up on formal night won't be able to acces all of the ship's dining options. They will have to stick to the buffets or Winter Garden and Garden Lounge bars.

The changes will start taking place in April and May.