US consumer prices rose 3.7% in the year to September, up from 3.4% in August, the Bureau of Labor Statistics reported. It is the highest annual inflation rate since May, when it reached 4.2%.

Gasoline accounted for more than half of the overall increase in prices and cost 34% more than a year earlier. Fuel oil was up 74%, while air fares rose 22.4%. Consumer prices increased 0.6% from August; annual core inflation, which excludes food and energy, reached 2.6%.

The figures are the final inflation report before the US midterm elections. Polls show widespread dissatisfaction with the Trump administration over living costs, leaving Republicans to face voters as inflation reaches its highest level since the spring.