The advertising watchdog has been asked to review its decision not to formally investigate a controversial Channel 4 billboard campaign for the Big Fat Gypsy Weddings documentary.
The campaign - which featured the words "Bigger. Fatter. Gypsier" printed over images of gypsy children - led to 372 complaints that it was offensive and racist.
The Advertising Standards Authority (ASA) decided against investigating the campaign earlier this year because it judged that although the ads "might not be to everyone's taste", the images and text reflected the tone and content of the programme, and were therefore unlikely to cause serious or widespread offence.
But the ASA's independent reviewer, Sir Hayden Phillips, has recommended that the ASA council review its decision following a request by the Irish Traveller Movement in Britain (ITMB).
David Enright, a partner with Howe & Co Solicitors who has been representing the ITMB, said: "This is a huge victory for the traveller and gypsy communities. Earlier this year, Channel 4 plastered the UK with their highly-offensive billboard advertising campaign.
"The advertising campaign caused outrage. Hundreds of travellers and gypsies complained to the ASA about these adverts, which they saw as being racially demeaning and damaging to them, their communities and their children."
He added: "Travellers and gypsies now wait to see if the ASA council considers that they are entitled to equal protection by the regulator."
ITMB director Yvonne MacNamara said: "We challenged the ASA to agree that it would never have permitted such an advertising campaign that bore the slogan 'Bigger Fatter Muslimer' or 'Bigger Fatter Blacker' or 'Bigger Fatter Jewier'."
The ASA said: "An independent review of ASA decisions can be requested by complainants and advertisers in any case involving an ASA council decision. The Irish Traveller Movement has exercised that right.
"The ASA council carefully and thoroughly assessed complaints about Channel 4's ads for the TV programme Big Fat Gypsy Weddings. It will give equally careful consideration to the points that the independent reviewer of ASA adjudications, Sir Hayden Phillips, brings to its attention."