On 20 April 2016 workers at the Meseta Central Service and Development Company SA de CV, which supplies staff, as a sub-contractor, to the Boleo Mining and Metals company, itself controlled by Korea Resources Corporation (KORES), went on strike to demand the withdrawal of the local leader of the national exploration and mining union the Sindicato Nacional de Trabajadores de la Exploración, Explotación y Beneficio de Minas en la República Mexicana (SNTEEBMRM) which had signed a protection contract with the company in 2007, preventing the organisation of free trade union elections.
On 23 April over 500 workers took part in an assembly at which they affiliated to the national mine and metal workers’ union the Sindicato Nacional de Trabajadores Mineros, Metalúrgicos, Siderúrgicos y Similares de la República Mexicana (SNTMMSSRM). This union submitted a request to the Federal Labour Board to be their official collective bargaining representative. On 5 May, the strike was disrupted by a large police contingent, despite the fact that the labour authorities had agreed to hold an election soon to allow the workers to vote on which union they wanted to represent them. On 20 May a meeting was held at the Federal Labour Board, but the Board subsequently refused to set a date for the election.
On 5 June the company dismissed 130 SNTMMSSRM supporters and on 9 June the representative of the Federal Labour Department in Baja California Sur, José Ernesto Álvarez Gámez, visited the mine to persuade the dismissed workers to accept severance pay. Seventy eight workers nonetheless submitted a legal request for reinstatement, but the Federal Labour Board failed to take any action.