National Union of Mine and Metal Workers of the Mexican Republic

The National Union of Mine, Metal, Steel and Allied Workers of the Mexican Republic, commonly known by its Spanish acronym SNTMMSSRM, is one of Mexico’s most historically significant industrial trade unions. It represents workers in coal and copper mining, as well as in iron, steel, and related metallurgical industries. Since its founding in the mid-twentieth century, the union has played a prominent role in Mexico’s labour movement, closely intertwined with state politics, industrial relations, and struggles over union democracy.

Foundation and Early Development

The SNTMMSSRM was founded in 1934, during a period of intense labour mobilisation following the Mexican Revolution. In 1936, it became affiliated with the newly created Confederation of Mexican Workers (CTM), the dominant national labour confederation aligned with the post-revolutionary state.
In its early years, the union’s leadership maintained a close alliance with Vicente Lombardo Toledano, the influential Marxist intellectual and head of the CTM. Lombardo Toledano was a central figure in shaping Mexico’s corporatist labour system, which integrated unions into the political framework of the ruling party in exchange for state recognition and protection.

Political Realignments and Internal Conflict

A major rupture occurred in 1949, when Lombardo Toledano broke with the CTM and established rival organisations, including the UGOCM (General Union of Workers and Peasants of Mexico) and the Popular Socialist Party. The SNTMMSSRM followed Lombardo Toledano into these new political and labour formations, alongside other important unions such as the railway workers’ and petroleum workers’ unions.
This realignment brought the union into direct conflict with the Institutional Revolutionary Party (PRI) and the CTM, which viewed Lombardo Toledano and his supporters as a serious challenge to state control over organised labour. In response, the Mexican government intervened in the union during the early 1950s, installing leadership figures known as charros, a term used in Mexican labour politics to describe corrupt, pro-government union bosses imposed to neutralise internal dissent and ensure political loyalty.

Era of Charro Leadership

The most prominent of these imposed leaders was Napoleón Gómez Sada, who served as president of the SNTMMSSRM for several decades. Under his leadership, the union became firmly aligned with government and employer interests, and internal opposition was largely suppressed.
For many years, rank-and-file resistance within the mining locals remained limited. One notable exception was Local 65 in Cananea, Sonora, which maintained a tradition of militancy and independence rooted in the region’s long history of labour struggle. More broadly, however, the union leadership faced little sustained challenge until the later decades of the twentieth century.

Reform Movements and Internal Opposition

Beginning in the 1970s and 1980s, a significant reform movement emerged within the union, driven primarily by steelworker locals rather than miners. These reformers advocated for greater internal democracy, transparency in financial management, and independence from state and employer control. Their efforts formed part of a wider trend of “new unionism” in Mexico, particularly in the steel and automotive sectors, where workers increasingly challenged corporatist labour arrangements and neoliberal economic reforms.
Although these movements achieved some local successes, they were unable to fully dislodge the entrenched national leadership structure of the SNTMMSSRM.

Contemporary Leadership and Controversy

In 2001, Napoleón Gómez Sada was succeeded as union leader by his son, Napoleón Gómez Urrutia, continuing a dynastic pattern of leadership. Gómez Urrutia’s tenure has been marked by intense controversy and legal disputes.
He has been accused of embezzling approximately US$55 million, funds that were allegedly intended for severance payments to workers at the Mexicana de Cananea mining company. According to court rulings, the money was diverted rather than distributed to the affected workers. Gómez Urrutia subsequently left Mexico and resided in Canada for several years, avoiding arrest while legal proceedings continued.
In April 2021, Gómez Urrutia was sentenced to return the disputed funds. Despite this ruling, he has not served a prison sentence and has remained free due to the parliamentary immunity he holds as a senator. His leadership continues to polarise opinion, with supporters portraying him as a defender of workers’ rights and critics viewing him as emblematic of corruption within Mexico’s union system.

Role in Mexican Labour Politics

The history of the SNTMMSSRM illustrates the broader dynamics of Mexican labour relations, particularly the long-standing tension between state corporatism and grassroots union democracy. For much of its existence, the union functioned as part of a system in which organised labour was subordinated to political authority in exchange for stability and limited material gains.
At the same time, internal reform efforts and persistent local resistance demonstrate that the union has also served as a site of struggle over representation, accountability, and workers’ autonomy. Its evolution reflects shifting economic conditions, from state-led industrialisation to privatisation and neoliberal restructuring, especially in the mining and steel sectors.