Le Hyaric is a member of the executive of the French Communist Party and also the federal secretary of the Communist federation in the Morbihan. In 2004, he led the PCF list in the West constituency. The PCF list obtained 4.1% in the constituency but no MEPs were elected.
In 2009, he was selected to lead the Left Front list in the Île-de-France constituency ahead of the 2009 European elections. His list won 6.32% of the vote and he was elected to the European Parliament.