Adidas, Esprit, and Gap Inc are among a coalition of 30 retailers and brands that have signed a new letter calling for an investigation into the recent violence in Cambodia's garment industry.

The group also includes American Eagle Outfitters, Bonmarché, C&A, Debenhams, Fifth & Pacific Companies, H&M, Inditex, Levi Strauss & Co, Lululemon Athletica, Migros, N Brown Group, New Balance, New Look, Nike, Orsay, Primark, Puma, PVH, Tchibo, Tesco, The Jones Group, The Walt Disney Company, Under Armour and Wal-Mart.

Global trade unions IndustriAll and Uni have also signed the letter, which backs the United Nation's call for a prompt and thorough investigation into the violence against protesting workers earlier this year.

"The investigation should ensure full accountability of any members of security forces found to have used disproportionate and excessive force and to take measures to prevent the repetition of such acts," the letter says.

"We urge the government to immediately engage employers and unions to negotiate a resolution to this crisis and to lay the foundation for credible and regular dialogue between workers, employers and government."

It goes on to say the government should address issues that have been the root cause of current and past conflicts. The letter also calls for respect for the right to freedom of association, a trade union law to be introduced, and a new wage-setting process. 

Cambodia Prime Minister Hun Sen should meet with senior representatives of the co-signed letter in the week of 3 February to discuss how they can help achieve these goals, the letter notes. 

"The global garment industry is changing rapidly, and industrial peace is required to rebuild our confidence in the Cambodian garment industry." 

The protests were sparked by disagreements on the minimum wage for garment works in the country. The Labour Advisory Committee has advised it should rise from US$80 per month to US$160 per month over the next five years. Trade unions, however, want the minimum level to be raised to US$160 immediately.

Last week, six leading trade associations representing North America's apparel brands and retailers also urged an end to the violence.

Groups who have also called for change include Clean Clothes Campaign, International Labor Rights Forum, Worker Rights Consortium, Maquila Solidarity Network, United Students Against Sweatshops, International Union League for Brand Responsibility, Workers United, SEIU, Framtiden i våre hender, and CNV Internationaal, The Netherlands.