Global unions and labour rights groups are calling for more brands to commit to the Rana Plaza compensation fund as the one year anniversary of the industrial disaster approaches.

The Pay Up! campaign wants all clothing brands who source from Bangladesh to contribute to the Rana Plaza Donors Trust Fund, which is collecting voluntary donations on behalf of the Rana Plaza Arrangement, and is overseen by the International Labour Organization (ILO).

According to the IndustriAll global union, only four brands have so far joined the Rana Plaza Arrangement set up to pay compensation to the injured and victims' families.

It was implemented following the collapse of the Rana Plaza factory building in April last year, which killed more than 1,100 people.

"Only two brands connected with Rana Plaza have paid into the fund," said global union assistant general secretary Monika Kemperle. "We implore the rest to pay up now. We urge people to write on their Facebook pages, write on the websites of their national media, and mobilise at the stores of these companies. It is time to name, shame and campaign."

IndustriAll said Mascot and El Corte Ingles are the only companies to have publicly contributed to the Rana Plaza Donors Trust Fund so far. It said there is a "long list" of brands connected with the disaster that are refusing to join the arrangement, including Auchan, Benetton, Carrefour, Lee Cooper, and Wal-Mart.

The union also highlighted Irish retailer Primark as having initially played "a leading role" in the industry's response to Rana Plaza, but said the group is now "wavering" after setting up its own scheme.

"On 24 April, one year will have passed since the horror of Rana Plaza. No more excuses. The fund is set up, the management of the fund is reliable, and every part of the mechanism has been negotiated and agreed by all concerned," said Kemperle.

"The support and commitment from all the major stakeholders has been attained. The only outstanding action now is for the brands to pay. The necessary total of US$40m is realistic. We need all supporters of this initiative to exert their strong influence over these image-conscious clothing companies."