The Left Bloc (Luxembourgish: Lénksblock, French: Bloc des Gauches) was a political alliance in the Chamber of Deputies of Luxembourg at the beginning of the 20th century. The "marriage of convenience" between the Social Democratic Party and the Liberal League was formed in 1908.
Its goal was to roll back the influence of the Church in public life, and specifically in schools. In this, it was successful against the "Right Bloc" (the later Party of the Right), when the Deputies of the two parties voted through the Education Law of 1912.
In this period, before universal suffrage had been introduced (in 1919), only 20,000 of the wealthier taxpayers had the right to vote. Thus, the centre of power was in the legislature, and this was a parliament of notables.
After their common goal had been reached, the two parties went their separate ways. In part, this was because the liberal, business-friendly world-view on the one hand, and socialist ideas on the other, were irreconcilable.