A campaign for a travel website has been cleared despite becoming the second most complained-about UK ad of all time for its use of the word "booking" as an apparent substitute for an expletive.

The Booking.com ad, which screened on television and in cinemas, featured holiday-goers arriving at their destinations while a voiceover said: "This holiday has been a year in the planning. And here you are standing, nay staring down your dreams ... The rest of your holiday hinges on the moment you walk through that door.

"The door opens, you hold your breath and then you realise. You got it right. You got it booking right. Because it doesn't get any better than this. It doesn't get any booking better than this. Look at the view, look at the booking view. This is exactly what you booking needed. Bask in the booking glory at over half a million properties. Planet Earth's number one accommodation site. Booking dot com, booking dot yeah."

The Advertising Standards Authority received 2,345 complaints from viewers, the majority of whom believed the word "booking" had been substituted in place of a swear word and was therefore offensive.

A number of complainants said the ads were likely to encourage swearing among children, and some reported seeing it during television programmes such as a Harry Potter film.

Others said they saw the ad at cinema screenings of Paddington and Night At The Museum: Secret Of The Tomb, questioning whether an audience of children was appropriate.

Booking.com claimed there was "no ambiguity" about the use of the word "booking", which it said was repeated throughout the ad to reinforce brand recognition.

They said the word was used at all times in a positive tone that conveyed enthusiasm and joy, rather than with any negative or derogatory tone often associated with swear words.

And it said that, as the ad did not feature any swear words or words that sounded like derivatives of swear words, they considered it could not be reasonably concluded that the ad condoned or encouraged swearing among children.

The Cinema Advertising Association (CAA) said they had borne in mind both the ad's potential to offend and the long history of double entendre and word substitution in British humour, which often appeared in pantomime and family entertainment and depended on the innocence or worldliness of viewers.

The CAA believed that young children did not generally possess the worldliness to conceive that the word "booking" could be synonymous with an expletive.

The ASA said it understood that the repetition of the word "booking" was intended to raise awareness of the Booking.com brand and had used word play in a comical way to express that message.

It said: "We noted that the word 'booking' was used throughout the ad in a variety of contexts that each lent themselves to substitution with an expletive, and that many viewers would understand the use of 'booking' as word play on the word 'f***ing'.

"However, we considered that the voiceover artist enunciated the word clearly and that it was sufficiently distinct so as not to be generally confused with the word 'f***ing'.

"Although we acknowledged that the placement of the word was redolent of the use of expletives, we noted that the ad did not expressly use any explicit language and therefore concluded that, although some viewers might find the connotation and wordplay distasteful, it was unlikely that the ad would cause serious or widespread offence."

The ASA added: "We understood that a small number of complainants had reported hearing their children swear after seeing the ad, but considered that because the ad did not contain any expletives this behaviour would not arise from the ad itself.

"Although some complainants were concerned that the ad was encouraging children to say 'booking' in the manner of the ad (and that some had reported this happening) we did not consider that this was tantamount to having encouraged these children to use expletives.

"We therefore concluded that the ad was unlikely to condone or encourage swearing amongst children."

It ruled that there was no further action required.

Paddy Power's Oscar Pistorius advert, which offered "money back if he walks", remains the most complained-about UK ad of all time.

The ad was immediately pulled and the ASA later upheld the 5,525 complaints and banned it last year.