A US senator affiliated with the country's conservative Tea Party movement – a network of political organisations advocating lower taxes and less government spending – has vowed to block the nomination of Janet Yellen as the next head of the Federal Reserve.

Rand Paul, a republican senator from Kentucky and son of Ron Paul, a former congressman and author of national bestseller End the Fed, said earlier this week that he would put a hold on Yellen's nomination unless his colleagues agree to a