Paddy Power is to be rapped by an advertising watchdog for a marketing stunt in which a lorry was emblazoned with the message "Immigrants, jump in the back!"

The controversial bookies posted a photo on Twitter of the truck parked at Dover in July, sparking accusations the firm was making light of the migrant crisis.

A number of people have since complained to the Advertising Standards Authority for Ireland (ASAI) which is reportedly poised to severely censure the Dublin-based company.

The one-off advertising campaign came at the height of the migrant crisis, as hundreds of desperate refugees risked their lives to make the perilous journey across the Channel from Calais into Kent.

The slogan said: "Immigrants, jump in the back! (but only if you're good at sport)" and featured images of England footballer Raheem Sterling, runner Mo Farah, rugby player Manu Tuilagi, cricketer Eoin Morgan and Wimbledon champ Andy Murray.

Paddy Power defended the stunt as "a bit of fun" but the Guardian reports a draft ASAI ruling found the firm to be in breach of three sections of Ireland's advertising code.

The sections are one about not causing general offence, one about not being offensive on the grounds of race, and one about seeking to be sensitive to diversity.

The ASAI concluded that while Paddy Power's social media followers would be used to the "edgy" humour, it was inappropriate for advertisers to use a vulnerable group to "attract attention".

A Paddy Power spokesman said the ad was not designed to cause offence, but merely to reference a long-running joke about Andy Murray's nationality.